€•Œsphinx.addnodes”Œdocument”“”)”}”(Œ rawsource”Œ”Œchildren”]”(Œtranslations”Œ LanguagesNode”“”)”}”(hhh]”(hŒpending_xref”“”)”}”(hhh]”Œdocutils.nodes”ŒText”“”ŒChinese (Simplified)”…””}”Œparent”hsbaŒ attributes”}”(Œids”]”Œclasses”]”Œnames”]”Œdupnames”]”Œbackrefs”]”Œ refdomain”Œstd”Œreftype”Œdoc”Œ reftarget”Œ"/translations/zh_CN/admin-guide/md”Œmodname”NŒ classname”NŒrefexplicit”ˆuŒtagname”hhhubh)”}”(hhh]”hŒChinese (Traditional)”…””}”hh2sbah}”(h]”h ]”h"]”h$]”h&]”Œ refdomain”h)Œreftype”h+Œ reftarget”Œ"/translations/zh_TW/admin-guide/md”Œmodname”NŒ classname”NŒrefexplicit”ˆuh1hhhubh)”}”(hhh]”hŒItalian”…””}”hhFsbah}”(h]”h ]”h"]”h$]”h&]”Œ refdomain”h)Œreftype”h+Œ reftarget”Œ"/translations/it_IT/admin-guide/md”Œmodname”NŒ classname”NŒrefexplicit”ˆuh1hhhubh)”}”(hhh]”hŒJapanese”…””}”hhZsbah}”(h]”h ]”h"]”h$]”h&]”Œ refdomain”h)Œreftype”h+Œ reftarget”Œ"/translations/ja_JP/admin-guide/md”Œmodname”NŒ classname”NŒrefexplicit”ˆuh1hhhubh)”}”(hhh]”hŒKorean”…””}”hhnsbah}”(h]”h ]”h"]”h$]”h&]”Œ refdomain”h)Œreftype”h+Œ reftarget”Œ"/translations/ko_KR/admin-guide/md”Œmodname”NŒ classname”NŒrefexplicit”ˆuh1hhhubh)”}”(hhh]”hŒSpanish”…””}”hh‚sbah}”(h]”h ]”h"]”h$]”h&]”Œ refdomain”h)Œreftype”h+Œ reftarget”Œ"/translations/sp_SP/admin-guide/md”Œmodname”NŒ classname”NŒrefexplicit”ˆuh1hhhubeh}”(h]”h ]”h"]”h$]”h&]”Œcurrent_language”ŒEnglish”uh1h hhŒ _document”hŒsource”NŒline”NubhŒsection”“”)”}”(hhh]”(hŒtitle”“”)”}”(hŒRAID arrays”h]”hŒRAID arrays”…””}”(hh¨hžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1h¦hh£hžhhŸŒ,,,,dev0,dev1,...,devn”h]”hŒTmd=,,,,dev0,dev1,...,devn”…””}”hj4sbah}”(h]”h ]”h"]”h$]”h&]”Œ xml:space”Œpreserve”uh1j2hŸh¶h Khh·hžhubhé)”}”(hŒ-for raid arrays with persistent superblocks::”h]”hŒ,for raid arrays with persistent superblocks:”…””}”(hjDhžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hèhŸh¶h Khh·hžhubj3)”}”(hŒ%md=,dev0,dev1,...,devn”h]”hŒ%md=,dev0,dev1,...,devn”…””}”hjRsbah}”(h]”h ]”h"]”h$]”h&]”jBjCuh1j2hŸh¶h Khh·hžhubhé)”}”(hŒ'or, to assemble a partitionable array::”h]”hŒ&or, to assemble a partitionable array:”…””}”(hj`hžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hèhŸh¶h Khh·hžhubj3)”}”(hŒ&md=d,dev0,dev1,...,devn”h]”hŒ&md=d,dev0,dev1,...,devn”…””}”hjnsbah}”(h]”h ]”h"]”h$]”h&]”jBjCuh1j2hŸh¶h Khh·hžhubh¢)”}”(hhh]”(h§)”}”(hŒ``md device no.``”h]”hŒliteral”“”)”}”(hjh]”hŒ md device no.”…””}”(hj…hžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1jƒhjubah}”(h]”h ]”h"]”h$]”h&]”uh1h¦hj|hžhhŸh¶h Kubhé)”}”(hŒThe number of the md device”h]”hŒThe number of the md device”…””}”(hj˜hžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hèhŸh¶h Khj|hžhubhŒtable”“”)”}”(hhh]”hŒtgroup”“”)”}”(hhh]”(hŒcolspec”“”)”}”(hhh]”h}”(h]”h ]”h"]”h$]”h&]”Œcolwidth”Kuh1j°hjubj±)”}”(hhh]”h}”(h]”h ]”h"]”h$]”h&]”Œcolwidth”K uh1j°hjubhŒthead”“”)”}”(hhh]”hŒrow”“”)”}”(hhh]”(hŒentry”“”)”}”(hhh]”hé)”}”(hŒ``md device no.``”h]”j„)”}”(hj×h]”hŒ md device no.”…””}”(hjÙhžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1jƒhjÕubah}”(h]”h ]”h"]”h$]”h&]”uh1hèhŸh¶h K hjÒubah}”(h]”h ]”h"]”h$]”h&]”uh1jÐhjÍubjÑ)”}”(hhh]”hé)”}”(hŒdevice”h]”hŒdevice”…””}”(hjõhžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hèhŸh¶h K hjòubah}”(h]”h ]”h"]”h$]”h&]”uh1jÐhjÍubeh}”(h]”h ]”h"]”h$]”h&]”uh1jËhjÈubah}”(h]”h ]”h"]”h$]”h&]”uh1jÆhjubhŒtbody”“”)”}”(hhh]”(jÌ)”}”(hhh]”(jÑ)”}”(hhh]”hé)”}”(hŒ0”h]”hŒ0”…””}”(hj hžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hèhŸh¶h K"hjubah}”(h]”h ]”h"]”h$]”h&]”uh1jÐhjubjÑ)”}”(hhh]”hé)”}”(hŒmd0”h]”hŒmd0”…””}”(hj7hžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hèhŸh¶h K"hj4ubah}”(h]”h ]”h"]”h$]”h&]”uh1jÐhjubeh}”(h]”h ]”h"]”h$]”h&]”uh1jËhjubjÌ)”}”(hhh]”(jÑ)”}”(hhh]”hé)”}”(hŒ1”h]”hŒ1”…””}”(hjWhžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hèhŸh¶h K#hjTubah}”(h]”h ]”h"]”h$]”h&]”uh1jÐhjQubjÑ)”}”(hhh]”hé)”}”(hŒmd1”h]”hŒmd1”…””}”(hjnhžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hèhŸh¶h K#hjkubah}”(h]”h ]”h"]”h$]”h&]”uh1jÐhjQubeh}”(h]”h ]”h"]”h$]”h&]”uh1jËhjubjÌ)”}”(hhh]”(jÑ)”}”(hhh]”hé)”}”(hŒ2”h]”hŒ2”…””}”(hjŽhžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hèhŸh¶h K$hj‹ubah}”(h]”h ]”h"]”h$]”h&]”uh1jÐhjˆubjÑ)”}”(hhh]”hé)”}”(hŒmd2”h]”hŒmd2”…””}”(hj¥hžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hèhŸh¶h K$hj¢ubah}”(h]”h ]”h"]”h$]”h&]”uh1jÐhjˆubeh}”(h]”h ]”h"]”h$]”h&]”uh1jËhjubjÌ)”}”(hhh]”(jÑ)”}”(hhh]”hé)”}”(hŒ3”h]”hŒ3”…””}”(hjÅhžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hèhŸh¶h K%hjÂubah}”(h]”h ]”h"]”h$]”h&]”uh1jÐhj¿ubjÑ)”}”(hhh]”hé)”}”(hŒmd3”h]”hŒmd3”…””}”(hjÜhžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hèhŸh¶h K%hjÙubah}”(h]”h ]”h"]”h$]”h&]”uh1jÐhj¿ubeh}”(h]”h ]”h"]”h$]”h&]”uh1jËhjubjÌ)”}”(hhh]”(jÑ)”}”(hhh]”hé)”}”(hŒ4”h]”hŒ4”…””}”(hjühžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hèhŸh¶h K&hjùubah}”(h]”h ]”h"]”h$]”h&]”uh1jÐhjöubjÑ)”}”(hhh]”hé)”}”(hŒmd4”h]”hŒmd4”…””}”(hjhžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hèhŸh¶h K&hjubah}”(h]”h ]”h"]”h$]”h&]”uh1jÐhjöubeh}”(h]”h ]”h"]”h$]”h&]”uh1jËhjubeh}”(h]”h ]”h"]”h$]”h&]”uh1jhjubeh}”(h]”h ]”h"]”h$]”h&]”Œcols”Kuh1j«hj¨ubah}”(h]”h ]”h"]”h$]”h&]”uh1j¦hj|hžhhŸh¶h Nubeh}”(h]”Œmd-device-no”ah ]”h"]”Œ md device no.”ah$]”h&]”uh1h¡hh·hžhhŸh¶h Kubh¢)”}”(hhh]”(h§)”}”(hŒ``raid level``”h]”j„)”}”(hjMh]”hŒ raid level”…””}”(hjOhžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1jƒhjKubah}”(h]”h ]”h"]”h$]”h&]”uh1h¦hjHhžhhŸh¶h K*ubhé)”}”(hŒlevel of the RAID array”h]”hŒlevel of the RAID array”…””}”(hjbhžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hèhŸh¶h K,hjHhžhubj§)”}”(hhh]”j¬)”}”(hhh]”(j±)”}”(hhh]”h}”(h]”h ]”h"]”h$]”h&]”Œcolwidth”Kuh1j°hjsubj±)”}”(hhh]”h}”(h]”h ]”h"]”h$]”h&]”Œcolwidth”K uh1j°hjsubjÇ)”}”(hhh]”jÌ)”}”(hhh]”(jÑ)”}”(hhh]”hé)”}”(hŒ``raid level``”h]”j„)”}”(hj•h]”hŒ raid level”…””}”(hj—hžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1jƒhj“ubah}”(h]”h ]”h"]”h$]”h&]”uh1hèhŸh¶h K/hjubah}”(h]”h ]”h"]”h$]”h&]”uh1jÐhjubjÑ)”}”(hhh]”hé)”}”(hŒlevel”h]”hŒlevel”…””}”(hj³hžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hèhŸh¶h K/hj°ubah}”(h]”h ]”h"]”h$]”h&]”uh1jÐhjubeh}”(h]”h ]”h"]”h$]”h&]”uh1jËhjŠubah}”(h]”h ]”h"]”h$]”h&]”uh1jÆhjsubj)”}”(hhh]”(jÌ)”}”(hhh]”(jÑ)”}”(hhh]”hé)”}”(hŒ-1”h]”hŒ-1”…””}”(hjÜhžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hèhŸh¶h K1hjÙubah}”(h]”h ]”h"]”h$]”h&]”uh1jÐhjÖubjÑ)”}”(hhh]”hé)”}”(hŒlinear mode”h]”hŒlinear mode”…””}”(hjóhžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hèhŸh¶h K1hjðubah}”(h]”h ]”h"]”h$]”h&]”uh1jÐhjÖubeh}”(h]”h ]”h"]”h$]”h&]”uh1jËhjÓubjÌ)”}”(hhh]”(jÑ)”}”(hhh]”hé)”}”(hj"h]”hŒ0”…””}”(hjhžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hèhŸh¶h K2hjubah}”(h]”h ]”h"]”h$]”h&]”uh1jÐhj ubjÑ)”}”(hhh]”hé)”}”(hŒstriped mode”h]”hŒstriped mode”…””}”(hj)hžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hèhŸh¶h K2hj&ubah}”(h]”h ]”h"]”h$]”h&]”uh1jÐhj ubeh}”(h]”h ]”h"]”h$]”h&]”uh1jËhjÓubeh}”(h]”h ]”h"]”h$]”h&]”uh1jhjsubeh}”(h]”h ]”h"]”h$]”h&]”Œcols”Kuh1j«hjpubah}”(h]”h ]”h"]”h$]”h&]”uh1j¦hjHhžhhŸh¶h Nubhé)”}”(hŒ;other modes are only supported with persistent super blocks”h]”hŒ;other modes are only supported with persistent super blocks”…””}”(hjVhžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hèhŸh¶h K5hjHhžhubeh}”(h]”Œ raid-level”ah ]”h"]”Œ raid level”ah$]”h&]”uh1h¡hh·hžhhŸh¶h K*ubh¢)”}”(hhh]”(h§)”}”(hŒ``chunk size factor``”h]”j„)”}”(hjqh]”hŒchunk size factor”…””}”(hjshžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1jƒhjoubah}”(h]”h ]”h"]”h$]”h&]”uh1h¦hjlhžhhŸh¶h K8ubhé)”}”(hŒ(raid-0 and raid-1 only)”h]”hŒ(raid-0 and raid-1 only)”…””}”(hj†hžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hèhŸh¶h K:hjlhžhubhé)”}”(hŒSet the chunk size as 4k << n.”h]”hŒSet the chunk size as 4k << n.”…””}”(hj”hžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hèhŸh¶h K) looks like this::”h]”(hŒ'A possible loadlin line (Harald Hoyer <”…””}”(hjYhžhhŸNh Nubhï)”}”(hŒHarryH@Royal.Net”h]”hŒHarryH@Royal.Net”…””}”(hjahžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”Œrefuri”Œmailto:HarryH@Royal.Net”uh1hîhjYubhŒ>) looks like this:”…””}”(hjYhžhhŸNh Nubeh}”(h]”h ]”h"]”h$]”h&]”uh1hèhŸh¶h KHhjÚhžhubj3)”}”(hŒLe:\loadlin\loadlin e:\zimage root=/dev/md0 md=0,0,4,0,/dev/hdb2,/dev/hdc3 ro”h]”hŒLe:\loadlin\loadlin e:\zimage root=/dev/md0 md=0,0,4,0,/dev/hdb2,/dev/hdc3 ro”…””}”hj{sbah}”(h]”h ]”h"]”h$]”h&]”jBjCuh1j2hŸh¶h KJhjÚhžhubeh}”(h]”Œdev0-to-devn”ah ]”h"]”Œdev0 to devn”ah$]”h&]”uh1h¡hh·hžhhŸh¶h KDubeh}”(h]”Œ!boot-time-assembly-of-raid-arrays”ah ]”h"]”Œ!boot time assembly of raid arrays”ah$]”h&]”uh1h¡hh£hžhhŸh¶h Kubh¢)”}”(hhh]”(h§)”}”(hŒ&Boot time autodetection of RAID arrays”h]”hŒ&Boot time autodetection of RAID arrays”…””}”(hjœhžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1h¦hj™hžhhŸh¶h KNubhé)”}”(hX@When md is compiled into the kernel (not as module), partitions of type 0xfd are scanned and automatically assembled into RAID arrays. This autodetection may be suppressed with the kernel parameter ``raid=noautodetect``. As of kernel 2.6.9, only drives with a type 0 superblock can be autodetected and run at boot time.”h]”(hŒÆWhen md is compiled into the kernel (not as module), partitions of type 0xfd are scanned and automatically assembled into RAID arrays. This autodetection may be suppressed with the kernel parameter ”…””}”(hjªhžhhŸNh Nubj„)”}”(hŒ``raid=noautodetect``”h]”hŒraid=noautodetect”…””}”(hj²hžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1jƒhjªubhŒe. As of kernel 2.6.9, only drives with a type 0 superblock can be autodetected and run at boot time.”…””}”(hjªhžhhŸNh Nubeh}”(h]”h ]”h"]”h$]”h&]”uh1hèhŸh¶h KPhj™hžhubhé)”}”(hŒ‚The kernel parameter ``raid=partitionable`` (or ``raid=part``) means that all auto-detected arrays are assembled as partitionable.”h]”(hŒThe kernel parameter ”…””}”(hjÊhžhhŸNh Nubj„)”}”(hŒ``raid=partitionable``”h]”hŒraid=partitionable”…””}”(hjÒhžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1jƒhjÊubhŒ (or ”…””}”(hjÊhžhhŸNh Nubj„)”}”(hŒ ``raid=part``”h]”hŒ raid=part”…””}”(hjähžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1jƒhjÊubhŒE) means that all auto-detected arrays are assembled as partitionable.”…””}”(hjÊhžhhŸNh Nubeh}”(h]”h ]”h"]”h$]”h&]”uh1hèhŸh¶h KVhj™hžhubeh}”(h]”Œ&boot-time-autodetection-of-raid-arrays”ah ]”h"]”Œ&boot time autodetection of raid arrays”ah$]”h&]”uh1h¡hh£hžhhŸh¶h KNubh¢)”}”(hhh]”(h§)”}”(hŒ+Boot time assembly of degraded/dirty arrays”h]”hŒ+Boot time assembly of degraded/dirty arrays”…””}”(hjhžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1h¦hjhžhhŸh¶h KZubhé)”}”(hX:If a raid5 or raid6 array is both dirty and degraded, it could have undetectable data corruption. This is because the fact that it is ``dirty`` means that the parity cannot be trusted, and the fact that it is degraded means that some datablocks are missing and cannot reliably be reconstructed (due to no parity).”h]”(hŒ‡If a raid5 or raid6 array is both dirty and degraded, it could have undetectable data corruption. This is because the fact that it is ”…””}”(hjhžhhŸNh Nubj„)”}”(hŒ ``dirty``”h]”hŒdirty”…””}”(hjhžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1jƒhjubhŒª means that the parity cannot be trusted, and the fact that it is degraded means that some datablocks are missing and cannot reliably be reconstructed (due to no parity).”…””}”(hjhžhhŸNh Nubeh}”(h]”h ]”h"]”h$]”h&]”uh1hèhŸh¶h K\hjhžhubhé)”}”(hŒÄFor this reason, md will normally refuse to start such an array. This requires the sysadmin to take action to explicitly start the array despite possible corruption. This is normally done with::”h]”hŒÃFor this reason, md will normally refuse to start such an array. This requires the sysadmin to take action to explicitly start the array despite possible corruption. This is normally done with:”…””}”(hj5hžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hèhŸh¶h Kbhjhžhubj3)”}”(hŒmdadm --assemble --force ....”h]”hŒmdadm --assemble --force ....”…””}”hjCsbah}”(h]”h ]”h"]”h$]”h&]”jBjCuh1j2hŸh¶h Kfhjhžhubhé)”}”(hXThis option is not really available if the array has the root filesystem on it. In order to support this booting from such an array, md supports a module parameter ``start_dirty_degraded`` which, when set to 1, bypassed the checks and will allows dirty degraded arrays to be started.”h]”(hŒ¥This option is not really available if the array has the root filesystem on it. In order to support this booting from such an array, md supports a module parameter ”…””}”(hjQhžhhŸNh Nubj„)”}”(hŒ``start_dirty_degraded``”h]”hŒstart_dirty_degraded”…””}”(hjYhžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1jƒhjQubhŒ_ which, when set to 1, bypassed the checks and will allows dirty degraded arrays to be started.”…””}”(hjQhžhhŸNh Nubeh}”(h]”h ]”h"]”h$]”h&]”uh1hèhŸh¶h Khhjhžhubhé)”}”(hŒISo, to boot with a root filesystem of a dirty degraded raid 5 or 6, use::”h]”hŒHSo, to boot with a root filesystem of a dirty degraded raid 5 or 6, use:”…””}”(hjqhžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hèhŸh¶h Knhjhžhubj3)”}”(hŒmd-mod.start_dirty_degraded=1”h]”hŒmd-mod.start_dirty_degraded=1”…””}”hjsbah}”(h]”h ]”h"]”h$]”h&]”jBjCuh1j2hŸh¶h Kphjhžhubeh}”(h]”Œ+boot-time-assembly-of-degraded-dirty-arrays”ah ]”h"]”Œ+boot time assembly of degraded/dirty arrays”ah$]”h&]”uh1h¡hh£hžhhŸh¶h KZubh¢)”}”(hhh]”(h§)”}”(hŒSuperblock formats”h]”hŒSuperblock formats”…””}”(hj˜hžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1h¦hj•hžhhŸh¶h Ktubhé)”}”(hŒ»The md driver can support a variety of different superblock formats. Currently, it supports superblock formats ``0.90.0`` and the ``md-1`` format introduced in the 2.5 development series.”h]”(hŒoThe md driver can support a variety of different superblock formats. Currently, it supports superblock formats ”…””}”(hj¦hžhhŸNh Nubj„)”}”(hŒ ``0.90.0``”h]”hŒ0.90.0”…””}”(hj®hžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1jƒhj¦ubhŒ and the ”…””}”(hj¦hžhhŸNh Nubj„)”}”(hŒ``md-1``”h]”hŒmd-1”…””}”(hjÀhžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1jƒhj¦ubhŒ1 format introduced in the 2.5 development series.”…””}”(hj¦hžhhŸNh Nubeh}”(h]”h ]”h"]”h$]”h&]”uh1hèhŸh¶h Kvhj•hžhubhé)”}”(hŒAThe kernel will autodetect which format superblock is being used.”h]”hŒAThe kernel will autodetect which format superblock is being used.”…””}”(hjØhžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hèhŸh¶h Kzhj•hžhubhé)”}”(hŒsSuperblock format ``0`` is treated differently to others for legacy reasons - it is the original superblock format.”h]”(hŒSuperblock format ”…””}”(hjæhžhhŸNh Nubj„)”}”(hŒ``0``”h]”hŒ0”…””}”(hjîhžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1jƒhjæubhŒ\ is treated differently to others for legacy reasons - it is the original superblock format.”…””}”(hjæhžhhŸNh Nubeh}”(h]”h ]”h"]”h$]”h&]”uh1hèhŸh¶h K|hj•hžhubeh}”(h]”Œsuperblock-formats”ah ]”h"]”Œsuperblock formats”ah$]”h&]”uh1h¡hh£hžhhŸh¶h Ktubh¢)”}”(hhh]”(h§)”}”(hŒ0General Rules - apply for all superblock formats”h]”hŒ0General Rules - apply for all superblock formats”…””}”(hjhžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1h¦hjhžhhŸh¶h Kubhé)”}”(hŒJAn array is ``created`` by writing appropriate superblocks to all devices.”h]”(hŒAn array is ”…””}”(hjhžhhŸNh Nubj„)”}”(hŒ``created``”h]”hŒcreated”…””}”(hj'hžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1jƒhjubhŒ3 by writing appropriate superblocks to all devices.”…””}”(hjhžhhŸNh Nubeh}”(h]”h ]”h"]”h$]”h&]”uh1hèhŸh¶h Kƒhjhžhubhé)”}”(hŒ”It is ``assembled`` by associating each of these devices with an particular md virtual device. Once it is completely assembled, it can be accessed.”h]”(hŒIt is ”…””}”(hj?hžhhŸNh Nubj„)”}”(hŒ ``assembled``”h]”hŒ assembled”…””}”(hjGhžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1jƒhj?ubhŒ by associating each of these devices with an particular md virtual device. Once it is completely assembled, it can be accessed.”…””}”(hj?hžhhŸNh Nubeh}”(h]”h ]”h"]”h$]”h&]”uh1hèhŸh¶h K†hjhžhubhé)”}”(hXAn array should be created by a user-space tool. This will write superblocks to all devices. It will usually mark the array as ``unclean``, or with some devices missing so that the kernel md driver can create appropriate redundancy (copying in raid 1, parity calculation in raid 4/5).”h]”(hŒAn array should be created by a user-space tool. This will write superblocks to all devices. It will usually mark the array as ”…””}”(hj_hžhhŸNh Nubj„)”}”(hŒ``unclean``”h]”hŒunclean”…””}”(hjghžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1jƒhj_ubhŒ’, or with some devices missing so that the kernel md driver can create appropriate redundancy (copying in raid 1, parity calculation in raid 4/5).”…””}”(hj_hžhhŸNh Nubeh}”(h]”h ]”h"]”h$]”h&]”uh1hèhŸh¶h KŠhjhžhubhé)”}”(hX`When an array is assembled, it is first initialized with the SET_ARRAY_INFO ioctl. This contains, in particular, a major and minor version number. The major version number selects which superblock format is to be used. The minor number might be used to tune handling of the format, such as suggesting where on each device to look for the superblock.”h]”hX`When an array is assembled, it is first initialized with the SET_ARRAY_INFO ioctl. This contains, in particular, a major and minor version number. The major version number selects which superblock format is to be used. The minor number might be used to tune handling of the format, such as suggesting where on each device to look for the superblock.”…””}”(hjhžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hèhŸh¶h Khjhžhubhé)”}”(hŒŽThen each device is added using the ADD_NEW_DISK ioctl. This provides, in particular, a major and minor number identifying the device to add.”h]”hŒŽThen each device is added using the ADD_NEW_DISK ioctl. This provides, in particular, a major and minor number identifying the device to add.”…””}”(hjhžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hèhŸh¶h K—hjhžhubhé)”}”(hŒ.The array is started with the RUN_ARRAY ioctl.”h]”hŒ.The array is started with the RUN_ARRAY ioctl.”…””}”(hj›hžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hèhŸh¶h K›hjhžhubhé)”}”(hŒOnce started, new devices can be added. They should have an appropriate superblock written to them, and then be passed in with ADD_NEW_DISK.”h]”hŒOnce started, new devices can be added. They should have an appropriate superblock written to them, and then be passed in with ADD_NEW_DISK.”…””}”(hj©hžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hèhŸh¶h Khjhžhubhé)”}”(hŒcDevices that have failed or are not yet active can be detached from an array using HOT_REMOVE_DISK.”h]”hŒcDevices that have failed or are not yet active can be detached from an array using HOT_REMOVE_DISK.”…””}”(hj·hžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hèhŸh¶h K¡hjhžhubeh}”(h]”Œ.general-rules-apply-for-all-superblock-formats”ah ]”h"]”Œ0general rules - apply for all superblock formats”ah$]”h&]”uh1h¡hh£hžhhŸh¶h Kubh¢)”}”(hhh]”(h§)”}”(hŒhSpecific Rules that apply to format-0 super block arrays, and arrays with no superblock (non-persistent)”h]”hŒhSpecific Rules that apply to format-0 super block arrays, and arrays with no superblock (non-persistent)”…””}”(hjÐhžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1h¦hjÍhžhhŸh¶h K¦ubhé)”}”(hŒ£An array can be ``created`` by describing the array (level, chunksize etc) in a SET_ARRAY_INFO ioctl. This must have ``major_version==0`` and ``raid_disks != 0``.”h]”(hŒAn array can be ”…””}”(hjÞhžhhŸNh Nubj„)”}”(hŒ``created``”h]”hŒcreated”…””}”(hjæhžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1jƒhjÞubhŒ[ by describing the array (level, chunksize etc) in a SET_ARRAY_INFO ioctl. This must have ”…””}”(hjÞhžhhŸNh Nubj„)”}”(hŒ``major_version==0``”h]”hŒmajor_version==0”…””}”(hjøhžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1jƒhjÞubhŒ and ”…””}”(hjÞhžhhŸNh Nubj„)”}”(hŒ``raid_disks != 0``”h]”hŒraid_disks != 0”…””}”(hj hžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1jƒhjÞubhŒ.”…””}”(hjÞhžhhŸNh Nubeh}”(h]”h ]”h"]”h$]”h&]”uh1hèhŸh¶h K¨hjÍhžhubhé)”}”(hŒ Then uninitialized devices can be added with ADD_NEW_DISK. The structure passed to ADD_NEW_DISK must specify the state of the device and its role in the array.”h]”hŒ Then uninitialized devices can be added with ADD_NEW_DISK. The structure passed to ADD_NEW_DISK must specify the state of the device and its role in the array.”…””}”(hj"hžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hèhŸh¶h K¬hjÍhžhubhé)”}”(hŒQOnce started with RUN_ARRAY, uninitialized spares can be added with HOT_ADD_DISK.”h]”hŒQOnce started with RUN_ARRAY, uninitialized spares can be added with HOT_ADD_DISK.”…””}”(hj0hžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hèhŸh¶h K°hjÍhžhubeh}”(h]”Œespecific-rules-that-apply-to-format-0-super-block-arrays-and-arrays-with-no-superblock-non-persistent”ah ]”h"]”Œhspecific rules that apply to format-0 super block arrays, and arrays with no superblock (non-persistent)”ah$]”h&]”uh1h¡hh£hžhhŸh¶h K¦ubh¢)”}”(hhh]”(h§)”}”(hŒMD devices in sysfs”h]”hŒMD devices in sysfs”…””}”(hjIhžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1h¦hjFhžhhŸh¶h Kµubhé)”}”(hŒFmd devices appear in sysfs (``/sys``) as regular block devices, e.g.::”h]”(hŒmd devices appear in sysfs (”…””}”(hjWhžhhŸNh Nubj„)”}”(hŒ``/sys``”h]”hŒ/sys”…””}”(hj_hžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1jƒhjWubhŒ!) as regular block devices, e.g.:”…””}”(hjWhžhhŸNh Nubeh}”(h]”h ]”h"]”h$]”h&]”uh1hèhŸh¶h K·hjFhžhubj3)”}”(hŒ/sys/block/md0”h]”hŒ/sys/block/md0”…””}”hjwsbah}”(h]”h ]”h"]”h$]”h&]”jBjCuh1j2hŸh¶h KºhjFhžhubhé)”}”(hŒ}Each ``md`` device will contain a subdirectory called ``md`` which contains further md-specific information about the device.”h]”(hŒEach ”…””}”(hj…hžhhŸNh Nubj„)”}”(hŒ``md``”h]”hŒmd”…””}”(hjhžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1jƒhj…ubhŒ+ device will contain a subdirectory called ”…””}”(hj…hžhhŸNh Nubj„)”}”(hŒ``md``”h]”hŒmd”…””}”(hjŸhžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1jƒhj…ubhŒA which contains further md-specific information about the device.”…””}”(hj…hžhhŸNh Nubeh}”(h]”h ]”h"]”h$]”h&]”uh1hèhŸh¶h K¼hjFhžhubhé)”}”(hŒAll md devices contain:”h]”hŒAll md devices contain:”…””}”(hj·hžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hèhŸh¶h K¿hjFhžhubhŒblock_quote”“”)”}”(hXO%level a text file indicating the ``raid level``. e.g. raid0, raid1, raid5, linear, multipath, faulty. If no raid level has been set yet (array is still being assembled), the value will reflect whatever has been written to it, which may be a name like the above, or may be a number such as ``0``, ``5``, etc. raid_disks a text file with a simple number indicating the number of devices in a fully functional array. If this is not yet known, the file will be empty. If an array is being resized this will contain the new number of devices. Some raid levels allow this value to be set while the array is active. This will reconfigure the array. Otherwise it can only be set while assembling an array. A change to this attribute will not be permitted if it would reduce the size of the array. To reduce the number of drives in an e.g. raid5, the array size must first be reduced by setting the ``array_size`` attribute. chunk_size This is the size in bytes for ``chunks`` and is only relevant to raid levels that involve striping (0,4,5,6,10). The address space of the array is conceptually divided into chunks and consecutive chunks are striped onto neighbouring devices. The size should be at least PAGE_SIZE (4k) and should be a power of 2. This can only be set while assembling an array layout The ``layout`` for the array for the particular level. This is simply a number that is interpreted differently by different levels. It can be written while assembling an array. array_size This can be used to artificially constrain the available space in the array to be less than is actually available on the combined devices. Writing a number (in Kilobytes) which is less than the available size will set the size. Any reconfiguration of the array (e.g. adding devices) will not cause the size to change. Writing the word ``default`` will cause the effective size of the array to be whatever size is actually available based on ``level``, ``chunk_size`` and ``component_size``. This can be used to reduce the size of the array before reducing the number of devices in a raid4/5/6, or to support external metadata formats which mandate such clipping. reshape_position This is either ``none`` or a sector number within the devices of the array where ``reshape`` is up to. If this is set, the three attributes mentioned above (raid_disks, chunk_size, layout) can potentially have 2 values, an old and a new value. If these values differ, reading the attribute returns:: new (old) and writing will effect the ``new`` value, leaving the ``old`` unchanged. component_size For arrays with data redundancy (i.e. not raid0, linear, faulty, multipath), all components must be the same size - or at least there must a size that they all provide space for. This is a key part or the geometry of the array. It is measured in sectors and can be read from here. Writing to this value may resize the array if the personality supports it (raid1, raid5, raid6), and if the component drives are large enough. metadata_version This indicates the format that is being used to record metadata about the array. It can be 0.90 (traditional format), 1.0, 1.1, 1.2 (newer format in varying locations) or ``none`` indicating that the kernel isn't managing metadata at all. Alternately it can be ``external:`` followed by a string which is set by user-space. This indicates that metadata is managed by a user-space program. Any device failure or other event that requires a metadata update will cause array activity to be suspended until the event is acknowledged. resync_start The point at which resync should start. If no resync is needed, this will be a very large number (or ``none`` since 2.6.30-rc1). At array creation it will default to 0, though starting the array as ``clean`` will set it much larger. new_dev This file can be written but not read. The value written should be a block device number as major:minor. e.g. 8:0 This will cause that device to be attached to the array, if it is available. It will then appear at md/dev-XXX (depending on the name of the device) and further configuration is then possible. safe_mode_delay When an md array has seen no write requests for a certain period of time, it will be marked as ``clean``. When another write request arrives, the array is marked as ``dirty`` before the write commences. This is known as ``safe_mode``. The ``certain period`` is controlled by this file which stores the period as a number of seconds. The default is 200msec (0.200). Writing a value of 0 disables safemode. array_state This file contains a single word which describes the current state of the array. In many cases, the state can be set by writing the word for the desired state, however some states cannot be explicitly set, and some transitions are not allowed. Select/poll works on this file. All changes except between Active_idle and active (which can be frequent and are not very interesting) are notified. active->active_idle is reported if the metadata is externally managed. clear No devices, no size, no level Writing is equivalent to STOP_ARRAY ioctl inactive May have some settings, but array is not active all IO results in error When written, doesn't tear down array, but just stops it suspended (not supported yet) All IO requests will block. The array can be reconfigured. Writing this, if accepted, will block until array is quiescent readonly no resync can happen. no superblocks get written. Write requests fail read-auto like readonly, but behaves like ``clean`` on a write request. clean no pending writes, but otherwise active. When written to inactive array, starts without resync If a write request arrives then if metadata is known, mark ``dirty`` and switch to ``active``. if not known, block and switch to write-pending If written to an active array that has pending writes, then fails. active fully active: IO and resync can be happening. When written to inactive array, starts with resync write-pending clean, but writes are blocked waiting for ``active`` to be written. active-idle like active, but no writes have been seen for a while (safe_mode_delay). bitmap/location This indicates where the write-intent bitmap for the array is stored. It can be one of ``none``, ``file`` or ``[+-]N``. ``file`` may later be extended to ``file:/file/name`` ``[+-]N`` means that many sectors from the start of the metadata. This is replicated on all devices. For arrays with externally managed metadata, the offset is from the beginning of the device. bitmap/chunksize The size, in bytes, of the chunk which will be represented by a single bit. For RAID456, it is a portion of an individual device. For RAID10, it is a portion of the array. For RAID1, it is both (they come to the same thing). bitmap/time_base The time, in seconds, between looking for bits in the bitmap to be cleared. In the current implementation, a bit will be cleared between 2 and 3 times ``time_base`` after all the covered blocks are known to be in-sync. bitmap/backlog When write-mostly devices are active in a RAID1, write requests to those devices proceed in the background - the filesystem (or other user of the device) does not have to wait for them. ``backlog`` sets a limit on the number of concurrent background writes. If there are more than this, new writes will by synchronous. bitmap/metadata This can be either ``internal`` or ``external``. ``internal`` is the default and means the metadata for the bitmap is stored in the first 256 bytes of the allocated space and is managed by the md module. ``external`` means that bitmap metadata is managed externally to the kernel (i.e. by some userspace program) bitmap/can_clear This is either ``true`` or ``false``. If ``true``, then bits in the bitmap will be cleared when the corresponding blocks are thought to be in-sync. If ``false``, bits will never be cleared. This is automatically set to ``false`` if a write happens on a degraded array, or if the array becomes degraded during a write. When metadata is managed externally, it should be set to true once the array becomes non-degraded, and this fact has been recorded in the metadata. consistency_policy This indicates how the array maintains consistency in case of unexpected shutdown. It can be: none Array has no redundancy information, e.g. raid0, linear. resync Full resync is performed and all redundancy is regenerated when the array is started after unclean shutdown. bitmap Resync assisted by a write-intent bitmap. journal For raid4/5/6, journal device is used to log transactions and replay after unclean shutdown. ppl For raid5 only, Partial Parity Log is used to close the write hole and eliminate resync. The accepted values when writing to this file are ``ppl`` and ``resync``, used to enable and disable PPL. uuid This indicates the UUID of the array in the following format: xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx ”h]”hÉ)”}”(hhh]”(hÎ)”}”(hX4level a text file indicating the ``raid level``. e.g. raid0, raid1, raid5, linear, multipath, faulty. If no raid level has been set yet (array is still being assembled), the value will reflect whatever has been written to it, which may be a name like the above, or may be a number such as ``0``, ``5``, etc. ”h]”(hÔ)”}”(hŒlevel”h]”hŒlevel”…””}”(hjÒhžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÓhŸh¶h KÇhjÎubhä)”}”(hhh]”hé)”}”(hX-a text file indicating the ``raid level``. e.g. raid0, raid1, raid5, linear, multipath, faulty. If no raid level has been set yet (array is still being assembled), the value will reflect whatever has been written to it, which may be a name like the above, or may be a number such as ``0``, ``5``, etc.”h]”(hŒa text file indicating the ”…””}”(hjãhžhhŸNh Nubj„)”}”(hŒ``raid level``”h]”hŒ raid level”…””}”(hjëhžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1jƒhjãubhŒò. e.g. raid0, raid1, raid5, linear, multipath, faulty. If no raid level has been set yet (array is still being assembled), the value will reflect whatever has been written to it, which may be a name like the above, or may be a number such as ”…””}”(hjãhžhhŸNh Nubj„)”}”(hŒ``0``”h]”hŒ0”…””}”(hjýhžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1jƒhjãubhŒ, ”…””}”(hjãhžhhŸNh Nubj„)”}”(hŒ``5``”h]”hŒ5”…””}”(hj hžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1jƒhjãubhŒ, etc.”…””}”(hjãhžhhŸNh Nubeh}”(h]”h ]”h"]”h$]”h&]”uh1hèhŸh¶h KÂhjàubah}”(h]”h ]”h"]”h$]”h&]”uh1hãhjÎubeh}”(h]”h ]”h"]”h$]”h&]”uh1hÍhŸh¶h KÇhjËubhÎ)”}”(hXfraid_disks a text file with a simple number indicating the number of devices in a fully functional array. If this is not yet known, the file will be empty. If an array is being resized this will contain the new number of devices. Some raid levels allow this value to be set while the array is active. This will reconfigure the array. Otherwise it can only be set while assembling an array. A change to this attribute will not be permitted if it would reduce the size of the array. To reduce the number of drives in an e.g. raid5, the array size must first be reduced by setting the ``array_size`` attribute. ”h]”(hÔ)”}”(hŒ raid_disks”h]”hŒ raid_disks”…””}”(hj7 hžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÓhŸh¶h KÔhj3 ubhä)”}”(hhh]”hé)”}”(hXZa text file with a simple number indicating the number of devices in a fully functional array. If this is not yet known, the file will be empty. If an array is being resized this will contain the new number of devices. Some raid levels allow this value to be set while the array is active. This will reconfigure the array. Otherwise it can only be set while assembling an array. A change to this attribute will not be permitted if it would reduce the size of the array. To reduce the number of drives in an e.g. raid5, the array size must first be reduced by setting the ``array_size`` attribute.”h]”(hXAa text file with a simple number indicating the number of devices in a fully functional array. If this is not yet known, the file will be empty. If an array is being resized this will contain the new number of devices. Some raid levels allow this value to be set while the array is active. This will reconfigure the array. Otherwise it can only be set while assembling an array. A change to this attribute will not be permitted if it would reduce the size of the array. To reduce the number of drives in an e.g. raid5, the array size must first be reduced by setting the ”…””}”(hjH hžhhŸNh Nubj„)”}”(hŒ``array_size``”h]”hŒ array_size”…””}”(hjP hžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1jƒhjH ubhŒ attribute.”…””}”(hjH hžhhŸNh Nubeh}”(h]”h ]”h"]”h$]”h&]”uh1hèhŸh¶h KÊhjE ubah}”(h]”h ]”h"]”h$]”h&]”uh1hãhj3 ubeh}”(h]”h ]”h"]”h$]”h&]”uh1hÍhŸh¶h KÔhjËubhÎ)”}”(hXtchunk_size This is the size in bytes for ``chunks`` and is only relevant to raid levels that involve striping (0,4,5,6,10). The address space of the array is conceptually divided into chunks and consecutive chunks are striped onto neighbouring devices. The size should be at least PAGE_SIZE (4k) and should be a power of 2. This can only be set while assembling an array ”h]”(hÔ)”}”(hŒ chunk_size”h]”hŒ chunk_size”…””}”(hjx hžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÓhŸh¶h KÜhjt ubhä)”}”(hhh]”hé)”}”(hXhThis is the size in bytes for ``chunks`` and is only relevant to raid levels that involve striping (0,4,5,6,10). The address space of the array is conceptually divided into chunks and consecutive chunks are striped onto neighbouring devices. The size should be at least PAGE_SIZE (4k) and should be a power of 2. This can only be set while assembling an array”h]”(hŒThis is the size in bytes for ”…””}”(hj‰ hžhhŸNh Nubj„)”}”(hŒ ``chunks``”h]”hŒchunks”…””}”(hj‘ hžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1jƒhj‰ ubhX@ and is only relevant to raid levels that involve striping (0,4,5,6,10). The address space of the array is conceptually divided into chunks and consecutive chunks are striped onto neighbouring devices. The size should be at least PAGE_SIZE (4k) and should be a power of 2. This can only be set while assembling an array”…””}”(hj‰ hžhhŸNh Nubeh}”(h]”h ]”h"]”h$]”h&]”uh1hèhŸh¶h K×hj† ubah}”(h]”h ]”h"]”h$]”h&]”uh1hãhjt ubeh}”(h]”h ]”h"]”h$]”h&]”uh1hÍhŸh¶h KÜhjËubhÎ)”}”(hŒºlayout The ``layout`` for the array for the particular level. This is simply a number that is interpreted differently by different levels. It can be written while assembling an array. ”h]”(hÔ)”}”(hŒlayout”h]”hŒlayout”…””}”(hj¹ hžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÓhŸh¶h Káhjµ ubhä)”}”(hhh]”hé)”}”(hŒ²The ``layout`` for the array for the particular level. This is simply a number that is interpreted differently by different levels. It can be written while assembling an array.”h]”(hŒThe ”…””}”(hjÊ hžhhŸNh Nubj„)”}”(hŒ ``layout``”h]”hŒlayout”…””}”(hjÒ hžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1jƒhjÊ ubhŒ¤ for the array for the particular level. This is simply a number that is interpreted differently by different levels. It can be written while assembling an array.”…””}”(hjÊ hžhhŸNh Nubeh}”(h]”h ]”h"]”h$]”h&]”uh1hèhŸh¶h KßhjÇ ubah}”(h]”h ]”h"]”h$]”h&]”uh1hãhjµ ubeh}”(h]”h ]”h"]”h$]”h&]”uh1hÍhŸh¶h KáhjËubhÎ)”}”(hX¥array_size This can be used to artificially constrain the available space in the array to be less than is actually available on the combined devices. Writing a number (in Kilobytes) which is less than the available size will set the size. Any reconfiguration of the array (e.g. adding devices) will not cause the size to change. Writing the word ``default`` will cause the effective size of the array to be whatever size is actually available based on ``level``, ``chunk_size`` and ``component_size``. This can be used to reduce the size of the array before reducing the number of devices in a raid4/5/6, or to support external metadata formats which mandate such clipping. ”h]”(hÔ)”}”(hŒ array_size”h]”hŒ array_size”…””}”(hjú hžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÓhŸh¶h Kïhjö ubhä)”}”(hhh]”(hé)”}”(hXìThis can be used to artificially constrain the available space in the array to be less than is actually available on the combined devices. Writing a number (in Kilobytes) which is less than the available size will set the size. Any reconfiguration of the array (e.g. adding devices) will not cause the size to change. Writing the word ``default`` will cause the effective size of the array to be whatever size is actually available based on ``level``, ``chunk_size`` and ``component_size``.”h]”(hXQThis can be used to artificially constrain the available space in the array to be less than is actually available on the combined devices. Writing a number (in Kilobytes) which is less than the available size will set the size. Any reconfiguration of the array (e.g. adding devices) will not cause the size to change. Writing the word ”…””}”(hj hžhhŸNh Nubj„)”}”(hŒ``default``”h]”hŒdefault”…””}”(hj hžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1jƒhj ubhŒ_ will cause the effective size of the array to be whatever size is actually available based on ”…””}”(hj hžhhŸNh Nubj„)”}”(hŒ ``level``”h]”hŒlevel”…””}”(hj% hžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1jƒhj ubhŒ, ”…””}”(hj hžhhŸNh Nubj„)”}”(hŒ``chunk_size``”h]”hŒ chunk_size”…””}”(hj7 hžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1jƒhj ubhŒ and ”…””}”(hj hžhhŸNh Nubj„)”}”(hŒ``component_size``”h]”hŒcomponent_size”…””}”(hjI hžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1jƒhj ubhŒ.”…””}”(hj hžhhŸNh Nubeh}”(h]”h ]”h"]”h$]”h&]”uh1hèhŸh¶h Kähj ubhé)”}”(hŒ«This can be used to reduce the size of the array before reducing the number of devices in a raid4/5/6, or to support external metadata formats which mandate such clipping.”h]”hŒ«This can be used to reduce the size of the array before reducing the number of devices in a raid4/5/6, or to support external metadata formats which mandate such clipping.”…””}”(hja hžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hèhŸh¶h Kíhj ubeh}”(h]”h ]”h"]”h$]”h&]”uh1hãhjö ubeh}”(h]”h ]”h"]”h$]”h&]”uh1hÍhŸh¶h KïhjËubhÎ)”}”(hX˜reshape_position This is either ``none`` or a sector number within the devices of the array where ``reshape`` is up to. If this is set, the three attributes mentioned above (raid_disks, chunk_size, layout) can potentially have 2 values, an old and a new value. If these values differ, reading the attribute returns:: new (old) and writing will effect the ``new`` value, leaving the ``old`` unchanged. ”h]”(hÔ)”}”(hŒreshape_position”h]”hŒreshape_position”…””}”(hj hžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÓhŸh¶h Kûhj{ ubhä)”}”(hhh]”(hé)”}”(hX-This is either ``none`` or a sector number within the devices of the array where ``reshape`` is up to. If this is set, the three attributes mentioned above (raid_disks, chunk_size, layout) can potentially have 2 values, an old and a new value. If these values differ, reading the attribute returns::”h]”(hŒThis is either ”…””}”(hj hžhhŸNh Nubj„)”}”(hŒ``none``”h]”hŒnone”…””}”(hj˜ hžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1jƒhj ubhŒ: or a sector number within the devices of the array where ”…””}”(hj hžhhŸNh Nubj„)”}”(hŒ``reshape``”h]”hŒreshape”…””}”(hjª hžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1jƒhj ubhŒÐ is up to. If this is set, the three attributes mentioned above (raid_disks, chunk_size, layout) can potentially have 2 values, an old and a new value. If these values differ, reading the attribute returns:”…””}”(hj hžhhŸNh Nubeh}”(h]”h ]”h"]”h$]”h&]”uh1hèhŸh¶h Kòhj ubj3)”}”(hŒ new (old)”h]”hŒ new (old)”…””}”hjÂ sbah}”(h]”h ]”h"]”h$]”h&]”jBjCuh1j2hŸh¶h Køhj ubhé)”}”(hŒIand writing will effect the ``new`` value, leaving the ``old`` unchanged.”h]”(hŒand writing will effect the ”…””}”(hjÐ hžhhŸNh Nubj„)”}”(hŒ``new``”h]”hŒnew”…””}”(hjØ hžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1jƒhjÐ ubhŒ value, leaving the ”…””}”(hjÐ hžhhŸNh Nubj„)”}”(hŒ``old``”h]”hŒold”…””}”(hjê hžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1jƒhjÐ ubhŒ unchanged.”…””}”(hjÐ hžhhŸNh Nubeh}”(h]”h ]”h"]”h$]”h&]”uh1hèhŸh¶h Kúhj ubeh}”(h]”h ]”h"]”h$]”h&]”uh1hãhj{ ubeh}”(h]”h ]”h"]”h$]”h&]”uh1hÍhŸh¶h KûhjËubhÎ)”}”(hXºcomponent_size For arrays with data redundancy (i.e. not raid0, linear, faulty, multipath), all components must be the same size - or at least there must a size that they all provide space for. This is a key part or the geometry of the array. It is measured in sectors and can be read from here. Writing to this value may resize the array if the personality supports it (raid1, raid5, raid6), and if the component drives are large enough. ”h]”(hÔ)”}”(hŒcomponent_size”h]”hŒcomponent_size”…””}”(hjhžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÓhŸh¶h Mhjubhä)”}”(hhh]”hé)”}”(hXªFor arrays with data redundancy (i.e. not raid0, linear, faulty, multipath), all components must be the same size - or at least there must a size that they all provide space for. This is a key part or the geometry of the array. It is measured in sectors and can be read from here. Writing to this value may resize the array if the personality supports it (raid1, raid5, raid6), and if the component drives are large enough.”h]”hXªFor arrays with data redundancy (i.e. not raid0, linear, faulty, multipath), all components must be the same size - or at least there must a size that they all provide space for. This is a key part or the geometry of the array. It is measured in sectors and can be read from here. Writing to this value may resize the array if the personality supports it (raid1, raid5, raid6), and if the component drives are large enough.”…””}”(hj#hžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hèhŸh¶h Kþhj ubah}”(h]”h ]”h"]”h$]”h&]”uh1hãhjubeh}”(h]”h ]”h"]”h$]”h&]”uh1hÍhŸh¶h MhjËubhÎ)”}”(hX&metadata_version This indicates the format that is being used to record metadata about the array. It can be 0.90 (traditional format), 1.0, 1.1, 1.2 (newer format in varying locations) or ``none`` indicating that the kernel isn't managing metadata at all. Alternately it can be ``external:`` followed by a string which is set by user-space. This indicates that metadata is managed by a user-space program. Any device failure or other event that requires a metadata update will cause array activity to be suspended until the event is acknowledged. ”h]”(hÔ)”}”(hŒmetadata_version”h]”hŒmetadata_version”…””}”(hjAhžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÓhŸh¶h Mhj=ubhä)”}”(hhh]”hé)”}”(hXThis indicates the format that is being used to record metadata about the array. It can be 0.90 (traditional format), 1.0, 1.1, 1.2 (newer format in varying locations) or ``none`` indicating that the kernel isn't managing metadata at all. Alternately it can be ``external:`` followed by a string which is set by user-space. This indicates that metadata is managed by a user-space program. Any device failure or other event that requires a metadata update will cause array activity to be suspended until the event is acknowledged.”h]”(hŒ¬This indicates the format that is being used to record metadata about the array. It can be 0.90 (traditional format), 1.0, 1.1, 1.2 (newer format in varying locations) or ”…””}”(hjRhžhhŸNh Nubj„)”}”(hŒ``none``”h]”hŒnone”…””}”(hjZhžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1jƒhjRubhŒT indicating that the kernel isnâ€™t managing metadata at all. Alternately it can be ”…””}”(hjRhžhhŸNh Nubj„)”}”(hŒ ``external:``”h]”hŒ external:”…””}”(hjlhžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1jƒhjRubhX followed by a string which is set by user-space. This indicates that metadata is managed by a user-space program. Any device failure or other event that requires a metadata update will cause array activity to be suspended until the event is acknowledged.”…””}”(hjRhžhhŸNh Nubeh}”(h]”h ]”h"]”h$]”h&]”uh1hèhŸh¶h MhjOubah}”(h]”h ]”h"]”h$]”h&]”uh1hãhj=ubeh}”(h]”h ]”h"]”h$]”h&]”uh1hÍhŸh¶h MhjËubhÎ)”}”(hŒøresync_start The point at which resync should start. If no resync is needed, this will be a very large number (or ``none`` since 2.6.30-rc1). At array creation it will default to 0, though starting the array as ``clean`` will set it much larger. ”h]”(hÔ)”}”(hŒresync_start”h]”hŒresync_start”…””}”(hj”hžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÓhŸh¶h Mhjubhä)”}”(hhh]”hé)”}”(hŒêThe point at which resync should start. If no resync is needed, this will be a very large number (or ``none`` since 2.6.30-rc1). At array creation it will default to 0, though starting the array as ``clean`` will set it much larger.”h]”(hŒfThe point at which resync should start. If no resync is needed, this will be a very large number (or ”…””}”(hj¥hžhhŸNh Nubj„)”}”(hŒ``none``”h]”hŒnone”…””}”(hjhžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1jƒhj¥ubhŒZ since 2.6.30-rc1). At array creation it will default to 0, though starting the array as ”…””}”(hj¥hžhhŸNh Nubj„)”}”(hŒ ``clean``”h]”hŒclean”…””}”(hj¿hžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1jƒhj¥ubhŒ will set it much larger.”…””}”(hj¥hžhhŸNh Nubeh}”(h]”h ]”h"]”h$]”h&]”uh1hèhŸh¶h Mhj¢ubah}”(h]”h ]”h"]”h$]”h&]”uh1hãhjubeh}”(h]”h ]”h"]”h$]”h&]”uh1hÍhŸh¶h MhjËubhÎ)”}”(hX>new_dev This file can be written but not read. The value written should be a block device number as major:minor. e.g. 8:0 This will cause that device to be attached to the array, if it is available. It will then appear at md/dev-XXX (depending on the name of the device) and further configuration is then possible. ”h]”(hÔ)”}”(hŒnew_dev”h]”hŒnew_dev”…””}”(hjçhžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÓhŸh¶h Mhjãubhä)”}”(hhh]”hé)”}”(hX5This file can be written but not read. The value written should be a block device number as major:minor. e.g. 8:0 This will cause that device to be attached to the array, if it is available. It will then appear at md/dev-XXX (depending on the name of the device) and further configuration is then possible.”h]”hX5This file can be written but not read. The value written should be a block device number as major:minor. e.g. 8:0 This will cause that device to be attached to the array, if it is available. It will then appear at md/dev-XXX (depending on the name of the device) and further configuration is then possible.”…””}”(hjøhžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hèhŸh¶h Mhjõubah}”(h]”h ]”h"]”h$]”h&]”uh1hãhjãubeh}”(h]”h ]”h"]”h$]”h&]”uh1hÍhŸh¶h MhjËubhÎ)”}”(hX¨safe_mode_delay When an md array has seen no write requests for a certain period of time, it will be marked as ``clean``. When another write request arrives, the array is marked as ``dirty`` before the write commences. This is known as ``safe_mode``. The ``certain period`` is controlled by this file which stores the period as a number of seconds. The default is 200msec (0.200). Writing a value of 0 disables safemode. ”h]”(hÔ)”}”(hŒsafe_mode_delay”h]”hŒsafe_mode_delay”…””}”(hjhžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÓhŸh¶h M%hjubhä)”}”(hhh]”hé)”}”(hX—When an md array has seen no write requests for a certain period of time, it will be marked as ``clean``. When another write request arrives, the array is marked as ``dirty`` before the write commences. This is known as ``safe_mode``. The ``certain period`` is controlled by this file which stores the period as a number of seconds. The default is 200msec (0.200). Writing a value of 0 disables safemode.”h]”(hŒ_When an md array has seen no write requests for a certain period of time, it will be marked as ”…””}”(hj'hžhhŸNh Nubj„)”}”(hŒ ``clean``”h]”hŒclean”…””}”(hj/hžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1jƒhj'ubhŒ>. When another write request arrives, the array is marked as ”…””}”(hj'hžhhŸNh Nubj„)”}”(hŒ ``dirty``”h]”hŒdirty”…””}”(hjAhžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1jƒhj'ubhŒ/ before the write commences. This is known as ”…””}”(hj'hžhhŸNh Nubj„)”}”(hŒ ``safe_mode``”h]”hŒ safe_mode”…””}”(hjShžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1jƒhj'ubhŒ. The ”…””}”(hj'hžhhŸNh Nubj„)”}”(hŒ``certain period``”h]”hŒcertain period”…””}”(hjehžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1jƒhj'ubhŒ” is controlled by this file which stores the period as a number of seconds. The default is 200msec (0.200). Writing a value of 0 disables safemode.”…””}”(hj'hžhhŸNh Nubeh}”(h]”h ]”h"]”h$]”h&]”uh1hèhŸh¶h Mhj$ubah}”(h]”h ]”h"]”h$]”h&]”uh1hãhjubeh}”(h]”h ]”h"]”h$]”h&]”uh1hÍhŸh¶h M%hjËubhÎ)”}”(hXarray_state This file contains a single word which describes the current state of the array. In many cases, the state can be set by writing the word for the desired state, however some states cannot be explicitly set, and some transitions are not allowed. Select/poll works on this file. All changes except between Active_idle and active (which can be frequent and are not very interesting) are notified. active->active_idle is reported if the metadata is externally managed. clear No devices, no size, no level Writing is equivalent to STOP_ARRAY ioctl inactive May have some settings, but array is not active all IO results in error When written, doesn't tear down array, but just stops it suspended (not supported yet) All IO requests will block. The array can be reconfigured. Writing this, if accepted, will block until array is quiescent readonly no resync can happen. no superblocks get written. Write requests fail read-auto like readonly, but behaves like ``clean`` on a write request. clean no pending writes, but otherwise active. When written to inactive array, starts without resync If a write request arrives then if metadata is known, mark ``dirty`` and switch to ``active``. if not known, block and switch to write-pending If written to an active array that has pending writes, then fails. active fully active: IO and resync can be happening. When written to inactive array, starts with resync write-pending clean, but writes are blocked waiting for ``active`` to be written. active-idle like active, but no writes have been seen for a while (safe_mode_delay). ”h]”(hÔ)”}”(hŒarray_state”h]”hŒarray_state”…””}”(hjhžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÓhŸh¶h M\hj‰ubhä)”}”(hhh]”(hé)”}”(hŒôThis file contains a single word which describes the current state of the array. In many cases, the state can be set by writing the word for the desired state, however some states cannot be explicitly set, and some transitions are not allowed.”h]”hŒôThis file contains a single word which describes the current state of the array. In many cases, the state can be set by writing the word for the desired state, however some states cannot be explicitly set, and some transitions are not allowed.”…””}”(hjžhžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hèhŸh¶h M(hj›ubhé)”}”(hŒÝSelect/poll works on this file. All changes except between Active_idle and active (which can be frequent and are not very interesting) are notified. active->active_idle is reported if the metadata is externally managed.”h]”hŒÝSelect/poll works on this file. All changes except between Active_idle and active (which can be frequent and are not very interesting) are notified. active->active_idle is reported if the metadata is externally managed.”…””}”(hj¬hžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hèhŸh¶h M-hj›ubhÉ)”}”(hhh]”(hÎ)”}”(hŒOclear No devices, no size, no level Writing is equivalent to STOP_ARRAY ioctl ”h]”(hÔ)”}”(hŒclear”h]”hŒclear”…””}”(hjÁhžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÓhŸh¶h M5hj½ubhä)”}”(hhh]”(hé)”}”(hŒNo devices, no size, no level”h]”hŒNo devices, no size, no level”…””}”(hjÒhžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hèhŸh¶h M3hjÏubhé)”}”(hŒ)Writing is equivalent to STOP_ARRAY ioctl”h]”hŒ)Writing is equivalent to STOP_ARRAY ioctl”…””}”(hjàhžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hèhŸh¶h M5hjÏubeh}”(h]”h ]”h"]”h$]”h&]”uh1hãhj½ubeh}”(h]”h ]”h"]”h$]”h&]”uh1hÍhŸh¶h M5hjºubhÎ)”}”(hŒ‹inactive May have some settings, but array is not active all IO results in error When written, doesn't tear down array, but just stops it ”h]”(hÔ)”}”(hŒinactive”h]”hŒinactive”…””}”(hjþhžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÓhŸh¶h M;hjúubhä)”}”(hhh]”(hé)”}”(hŒGMay have some settings, but array is not active all IO results in error”h]”hŒGMay have some settings, but array is not active all IO results in error”…””}”(hj hžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hèhŸh¶h M8hj ubhé)”}”(hŒ8When written, doesn't tear down array, but just stops it”h]”hŒ:When written, doesnâ€™t tear down array, but just stops it”…””}”(hj hžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hèhŸh¶h M;hj ubeh}”(h]”h ]”h"]”h$]”h&]”uh1hãhjúubeh}”(h]”h ]”h"]”h$]”h&]”uh1hÍhŸh¶h M;hjºubhÎ)”}”(hŒ™suspended (not supported yet) All IO requests will block. The array can be reconfigured. Writing this, if accepted, will block until array is quiescent ”h]”(hÔ)”}”(hŒsuspended (not supported yet)”h]”hŒsuspended (not supported yet)”…””}”(hj; hžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÓhŸh¶h M@hj7 ubhä)”}”(hhh]”(hé)”}”(hŒ:All IO requests will block. The array can be reconfigured.”h]”hŒ:All IO requests will block. The array can be reconfigured.”…””}”(hjL hžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hèhŸh¶h M>hjI ubhé)”}”(hŒ>Writing this, if accepted, will block until array is quiescent”h]”hŒ>Writing this, if accepted, will block until array is quiescent”…””}”(hjZ hžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hèhŸh¶h M@hjI ubeh}”(h]”h ]”h"]”h$]”h&]”uh1hãhj7 ubeh}”(h]”h ]”h"]”h$]”h&]”uh1hÍhŸh¶h M@hjºubhÎ)”}”(hŒQreadonly no resync can happen. no superblocks get written. Write requests fail ”h]”(hÔ)”}”(hŒreadonly”h]”hŒreadonly”…””}”(hjx hžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÓhŸh¶h MEhjt ubhä)”}”(hhh]”(hé)”}”(hŒ2no resync can happen. no superblocks get written.”h]”hŒ2no resync can happen. no superblocks get written.”…””}”(hj‰ hžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hèhŸh¶h MChj† ubhé)”}”(hŒWrite requests fail”h]”hŒWrite requests fail”…””}”(hj— hžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hèhŸh¶h MEhj† ubeh}”(h]”h ]”h"]”h$]”h&]”uh1hãhjt ubeh}”(h]”h ]”h"]”h$]”h&]”uh1hÍhŸh¶h MEhjºubhÎ)”}”(hŒHread-auto like readonly, but behaves like ``clean`` on a write request. ”h]”(hÔ)”}”(hŒ read-auto”h]”hŒ read-auto”…””}”(hjµ hžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÓhŸh¶h MHhj± ubhä)”}”(hhh]”hé)”}”(hŒ=like readonly, but behaves like ``clean`` on a write request.”h]”(hŒ like readonly, but behaves like ”…””}”(hjÆ hžhhŸNh Nubj„)”}”(hŒ ``clean``”h]”hŒclean”…””}”(hjÎ hžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1jƒhjÆ ubhŒ on a write request.”…””}”(hjÆ hžhhŸNh Nubeh}”(h]”h ]”h"]”h$]”h&]”uh1hèhŸh¶h MHhjÃ ubah}”(h]”h ]”h"]”h$]”h&]”uh1hãhj± ubeh}”(h]”h ]”h"]”h$]”h&]”uh1hÍhŸh¶h MHhjºubhÎ)”}”(hX9clean no pending writes, but otherwise active. When written to inactive array, starts without resync If a write request arrives then if metadata is known, mark ``dirty`` and switch to ``active``. if not known, block and switch to write-pending If written to an active array that has pending writes, then fails.”h]”(hÔ)”}”(hŒclean”h]”hŒclean”…””}”(hjö hžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÓhŸh¶h MRhjò ubhä)”}”(hhh]”(hé)”}”(hŒ(no pending writes, but otherwise active.”h]”hŒ(no pending writes, but otherwise active.”…””}”(hjhžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hèhŸh¶h MKhjubhé)”}”(hŒ5When written to inactive array, starts without resync”h]”hŒ5When written to inactive array, starts without resync”…””}”(hjhžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hèhŸh¶h MMhjubhé)”}”(hŒŽIf a write request arrives then if metadata is known, mark ``dirty`` and switch to ``active``. if not known, block and switch to write-pending”h]”(hŒ;If a write request arrives then if metadata is known, mark ”…””}”(hj#hžhhŸNh Nubj„)”}”(hŒ ``dirty``”h]”hŒdirty”…””}”(hj+hžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1jƒhj#ubhŒ and switch to ”…””}”(hj#hžhhŸNh Nubj„)”}”(hŒ ``active``”h]”hŒactive”…””}”(hj=hžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1jƒhj#ubhŒ1. if not known, block and switch to write-pending”…””}”(hj#hžhhŸNh Nubeh}”(h]”h ]”h"]”h$]”h&]”uh1hèhŸh¶h MOhjubhé)”}”(hŒBIf written to an active array that has pending writes, then fails.”h]”hŒBIf written to an active array that has pending writes, then fails.”…””}”(hjUhžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hèhŸh¶h MShjubeh}”(h]”h ]”h"]”h$]”h&]”uh1hãhjò ubeh}”(h]”h ]”h"]”h$]”h&]”uh1hÍhŸh¶h MRhjºubhÎ)”}”(hŒhactive fully active: IO and resync can be happening. When written to inactive array, starts with resync ”•h]”(hÔ)”}”(hŒactive”h]”hŒactive”…””}”(hjshžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÓhŸh¶h MVhjoubhä)”}”(hhh]”hé)”}”(hŒ`fully active: IO and resync can be happening. When written to inactive array, starts with resync”h]”hŒ`fully active: IO and resync can be happening. When written to inactive array, starts with resync”…””}”(hj„hžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hèhŸh¶h MUhjubah}”(h]”h ]”h"]”h$]”h&]”uh1hãhjoubeh}”(h]”h ]”h"]”h$]”h&]”uh1hÍhŸh¶h MVhjºubhÎ)”}”(hŒRwrite-pending clean, but writes are blocked waiting for ``active`` to be written. ”h]”(hÔ)”}”(hŒ write-pending”h]”hŒ write-pending”…””}”(hj¢hžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÓhŸh¶h MYhjžubhä)”}”(hhh]”hé)”}”(hŒCclean, but writes are blocked waiting for ``active`` to be written.”h]”(hŒ*clean, but writes are blocked waiting for ”…””}”(hj³hžhhŸNh Nubj„)”}”(hŒ ``active``”h]”hŒactive”…””}”(hj»hžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1jƒhj³ubhŒ to be written.”…””}”(hj³hžhhŸNh Nubeh}”(h]”h ]”h"]”h$]”h&]”uh1hèhŸh¶h MYhj°ubah}”(h]”h ]”h"]”h$]”h&]”uh1hãhjžubeh}”(h]”h ]”h"]”h$]”h&]”uh1hÍhŸh¶h MYhjºubhÎ)”}”(hŒUactive-idle like active, but no writes have been seen for a while (safe_mode_delay). ”h]”(hÔ)”}”(hŒactive-idle”h]”hŒactive-idle”…””}”(hjãhžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÓhŸh¶h M\hjßubhä)”}”(hhh]”hé)”}”(hŒHlike active, but no writes have been seen for a while (safe_mode_delay).”h]”hŒHlike active, but no writes have been seen for a while (safe_mode_delay).”…””}”(hjôhžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hèhŸh¶h M\hjñubah}”(h]”h ]”h"]”h$]”h&]”uh1hãhjßubeh}”(h]”h ]”h"]”h$]”h&]”uh1hÍhŸh¶h M\hjºubeh}”(h]”h ]”h"]”h$]”h&]”uh1hÈhj›ubeh}”(h]”h ]”h"]”h$]”h&]”uh1hãhj‰ubeh}”(h]”h ]”h"]”h$]”h&]”uh1hÍhŸh¶h M\hjËubhÎ)”}”(hXƒbitmap/location This indicates where the write-intent bitmap for the array is stored. It can be one of ``none``, ``file`` or ``[+-]N``. ``file`` may later be extended to ``file:/file/name`` ``[+-]N`` means that many sectors from the start of the metadata. This is replicated on all devices. For arrays with externally managed metadata, the offset is from the beginning of the device. ”h]”(hÔ)”}”(hŒbitmap/location”h]”hŒbitmap/location”…””}”(hj$hžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÓhŸh¶h Mhhj ubhä)”}”(hhh]”(hé)”}”(hŒEThis indicates where the write-intent bitmap for the array is stored.”h]”hŒEThis indicates where the write-intent bitmap for the array is stored.”…””}”(hj5hžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hèhŸh¶h M_hj2ubhé)”}”(hŒ©It can be one of ``none``, ``file`` or ``[+-]N``. ``file`` may later be extended to ``file:/file/name`` ``[+-]N`` means that many sectors from the start of the metadata.”h]”(hŒIt can be one of ”…””}”(hjChžhhŸNh Nubj„)”}”(hŒ``none``”h]”hŒnone”…””}”(hjKhžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1jƒhjCubhŒ, ”…””}”(hjChžhhŸNh Nubj„)”}”(hŒ``file``”h]”hŒfile”…””}”(hj]hžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1jƒhjCubhŒ or ”…””}”(hjChžhhŸNh Nubj„)”}”(hŒ ``[+-]N``”h]”hŒ[+-]N”…””}”(hjohžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1jƒhjCubhŒ. ”…””}”(hjChžhhŸNh Nubj„)”}”(hŒ``file``”h]”hŒfile”…””}”(hjhžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1jƒhjCubhŒ may later be extended to ”…””}”(hjChžhhŸNh Nubj„)”}”(hŒ``file:/file/name``”h]”hŒfile:/file/name”…””}”(hj“hžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1jƒhjCubhŒ ”…””}”(hjChžhhŸNh Nubj„)”}”(hŒ ``[+-]N``”h]”hŒ[+-]N”…””}”(hj¥hžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1jƒhjCubhŒ8 means that many sectors from the start of the metadata.”…””}”(hjChžhhŸNh Nubeh}”(h]”h ]”h"]”h$]”h&]”uh1hèhŸh¶h Mbhj2ubhé)”}”(hŒ€This is replicated on all devices. For arrays with externally managed metadata, the offset is from the beginning of the device.”h]”hŒ€This is replicated on all devices. For arrays with externally managed metadata, the offset is from the beginning of the device.”…””}”(hj½hžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hèhŸh¶h Mfhj2ubeh}”(h]”h ]”h"]”h$]”h&]”uh1hãhj ubeh}”(h]”h ]”h"]”h$]”h&]”uh1hÍhŸh¶h MhhjËubhÎ)”}”(hŒôbitmap/chunksize The size, in bytes, of the chunk which will be represented by a single bit. For RAID456, it is a portion of an individual device. For RAID10, it is a portion of the array. For RAID1, it is both (they come to the same thing). ”h]”(hÔ)”}”(hŒbitmap/chunksize”h]”hŒbitmap/chunksize”…””}”(hjÛhžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÓhŸh¶h Mnhj×ubhä)”}”(hhh]”hé)”}”(hŒâThe size, in bytes, of the chunk which will be represented by a single bit. For RAID456, it is a portion of an individual device. For RAID10, it is a portion of the array. For RAID1, it is both (they come to the same thing).”h]”hŒâThe size, in bytes, of the chunk which will be represented by a single bit. For RAID456, it is a portion of an individual device. For RAID10, it is a portion of the array. For RAID1, it is both (they come to the same thing).”…””}”(hjìhžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hèhŸh¶h Mkhjéubah}”(h]”h ]”h"]”h$]”h&]”uh1hãhj×ubeh}”(h]”h ]”h"]”h$]”h&]”uh1hÍhŸh¶h MnhjËubhÎ)”}”(hŒìbitmap/time_base The time, in seconds, between looking for bits in the bitmap to be cleared. In the current implementation, a bit will be cleared between 2 and 3 times ``time_base`` after all the covered blocks are known to be in-sync. ”h]”(hÔ)”}”(hŒbitmap/time_base”h]”hŒbitmap/time_base”…””}”(hj hžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÓhŸh¶h Mthjubhä)”}”(hhh]”hé)”}”(hŒÚThe time, in seconds, between looking for bits in the bitmap to be cleared. In the current implementation, a bit will be cleared between 2 and 3 times ``time_base`` after all the covered blocks are known to be in-sync.”h]”(hŒ—The time, in seconds, between looking for bits in the bitmap to be cleared. In the current implementation, a bit will be cleared between 2 and 3 times ”…””}”(hjhžhhŸNh Nubj„)”}”(hŒ ``time_base``”h]”hŒ time_base”…””}”(hj#hžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1jƒhjubhŒ6 after all the covered blocks are known to be in-sync.”…””}”(hjhžhhŸNh Nubeh}”(h]”h ]”h"]”h$]”h&]”uh1hèhŸh¶h Mqhjubah}”(h]”h ]”h"]”h$]”h&]”uh1hãhjubeh}”(h]”h ]”h"]”h$]”h&]”uh1hÍhŸh¶h MthjËubhÎ)”}”(hXObitmap/backlog When write-mostly devices are active in a RAID1, write requests to those devices proceed in the background - the filesystem (or other user of the device) does not have to wait for them. ``backlog`` sets a limit on the number of concurrent background writes. If there are more than this, new writes will by synchronous. ”h]”(hÔ)”}”(hŒbitmap/backlog”h]”hŒbitmap/backlog”…””}”(hjKhžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÓhŸh¶h M|hjGubhä)”}”(hhh]”hé)”}”(hX?When write-mostly devices are active in a RAID1, write requests to those devices proceed in the background - the filesystem (or other user of the device) does not have to wait for them. ``backlog`` sets a limit on the number of concurrent background writes. If there are more than this, new writes will by synchronous.”h]”(hŒºWhen write-mostly devices are active in a RAID1, write requests to those devices proceed in the background - the filesystem (or other user of the device) does not have to wait for them. ”…””}”(hj\hžhhŸNh Nubj„)”}”(hŒ``backlog``”h]”hŒbacklog”…””}”(hjdhžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1jƒhj\ubhŒz sets a limit on the number of concurrent background writes. If there are more than this, new writes will by synchronous.”…””}”(hj\hžhhŸNh Nubeh}”(h]”h ]”h"]”h$]”h&]”uh1hèhŸh¶h MwhjYubah}”(h]”h ]”h"]”h$]”h&]”uh1hãhjGubeh}”(h]”h ]”h"]”h$]”h&]”uh1hÍhŸh¶h M|hjËubhÎ)”}”(hXUbitmap/metadata This can be either ``internal`` or ``external``. ``internal`` is the default and means the metadata for the bitmap is stored in the first 256 bytes of the allocated space and is managed by the md module. ``external`` means that bitmap metadata is managed externally to the kernel (i.e. by some userspace program) ”h]”(hÔ)”}”(hŒbitmap/metadata”h]”hŒbitmap/metadata”…””}”(hjŒhžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÓhŸh¶h Mˆhjˆubhä)”}”(hhh]”(hé)”}”(hŒ0This can be either ``internal`` or ``external``.”h]”(hŒThis can be either ”…””}”(hjhžhhŸNh Nubj„)”}”(hŒ``internal``”h]”hŒinternal”…””}”(hj¥hžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1jƒhjubhŒ or ”…””}”(hjhžhhŸNh Nubj„)”}”(hŒ``external``”h]”hŒexternal”…””}”(hj·hžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1jƒhjubhŒ.”…””}”(hjhžhhŸNh Nubeh}”(h]”h ]”h"]”h$]”h&]”uh1hèhŸh¶h MhjšubhÉ)”}”(hhh]”(hÎ)”}”(hŒ›``internal`` is the default and means the metadata for the bitmap is stored in the first 256 bytes of the allocated space and is managed by the md module. ”h]”(hÔ)”}”(hŒ``internal``”h]”j„)”}”(hjØh]”hŒinternal”…””}”(hjÚhžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1jƒhjÖubah}”(h]”h ]”h"]”h$]”h&]”uh1hÓhŸh¶h M„hjÒubhä)”}”(hhh]”hé)”}”(hŒis the default and means the metadata for the bitmap is stored in the first 256 bytes of the allocated space and is managed by the md module.”h]”hŒis the default and means the metadata for the bitmap is stored in the first 256 bytes of the allocated space and is managed by the md module.”…””}”(hjðhžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hèhŸh¶h M‚hjíubah}”(h]”h ]”h"]”h$]”h&]”uh1hãhjÒubeh}”(h]”h ]”h"]”h$]”h&]”uh1hÍhŸh¶h M„hjÏubhÎ)”}”(hŒm``external`` means that bitmap metadata is managed externally to the kernel (i.e. by some userspace program) ”h]”(hÔ)”}”(hŒ``external``”h]”j„)”}”(hjh]”hŒexternal”…””}”(hjhžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1jƒhjubah}”(h]”h ]”h"]”h$]”h&]”uh1hÓhŸh¶h Mˆhj ubhä)”}”(hhh]”hé)”}”(hŒ_means that bitmap metadata is managed externally to the kernel (i.e. by some userspace program)”h]”hŒ_means that bitmap metadata is managed externally to the kernel (i.e. by some userspace program)”…””}”(hj(hžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hèhŸh¶h M‡hj%ubah}”(h]”h ]”h"]”h$]”h&]”uh1hãhj ubeh}”(h]”h ]”h"]”h$]”h&]”uh1hÍhŸh¶h MˆhjÏubeh}”(h]”h ]”h"]”h$]”h&]”uh1hÈhjšubeh}”(h]”h ]”h"]”h$]”h&]”uh1hãhjˆubeh}”(h]”h ]”h"]”h$]”h&]”uh1hÍhŸh¶h MˆhjËubhÎ)”}”(hXåbitmap/can_clear This is either ``true`` or ``false``. If ``true``, then bits in the bitmap will be cleared when the corresponding blocks are thought to be in-sync. If ``false``, bits will never be cleared. This is automatically set to ``false`` if a write happens on a degraded array, or if the array becomes degraded during a write. When metadata is managed externally, it should be set to true once the array becomes non-degraded, and this fact has been recorded in the metadata. ”h]”(hÔ)”}”(hŒbitmap/can_clear”h]”hŒbitmap/can_clear”…””}”(hjXhžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÓhŸh¶h M’hjTubhä)”}”(hhh]”hé)”}”(hXÓThis is either ``true`` or ``false``. If ``true``, then bits in the bitmap will be cleared when the corresponding blocks are thought to be in-sync. If ``false``, bits will never be cleared. This is automatically set to ``false`` if a write happens on a degraded array, or if the array becomes degraded during a write. When metadata is managed externally, it should be set to true once the array becomes non-degraded, and this fact has been recorded in the metadata.”h]”(hŒThis is either ”…””}”(hjihžhhŸNh Nubj„)”}”(hŒ``true``”h]”hŒtrue”…””}”(hjqhžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1jƒhjiubhŒ or ”…””}”(hjihžhhŸNh Nubj„)”}”(hŒ ``false``”h]”hŒfalse”…””}”(hjƒhžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1jƒhjiubhŒ. If ”…””}”(hjihžhhŸNh Nubj„)”}”(hŒ``true``”h]”hŒtrue”…””}”(hj•hžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1jƒhjiubhŒg, then bits in the bitmap will be cleared when the corresponding blocks are thought to be in-sync. If ”…””}”(hjihžhhŸNh Nubj„)”}”(hŒ ``false``”h]”hŒfalse”…””}”(hj§hžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1jƒhjiubhŒ;, bits will never be cleared. This is automatically set to ”…””}”(hjihžhhŸNh Nubj„)”}”(hŒ ``false``”h]”hŒfalse”…””}”(hj¹hžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1jƒhjiubhŒí if a write happens on a degraded array, or if the array becomes degraded during a write. When metadata is managed externally, it should be set to true once the array becomes non-degraded, and this fact has been recorded in the metadata.”…””}”(hjihžhhŸNh Nubeh}”(h]”h ]”h"]”h$]”h&]”uh1hèhŸh¶h M‹hjfubah}”(h]”h ]”h"]”h$]”h&]”uh1hãhjTubeh}”(h]”h ]”h"]”h$]”h&]”uh1hÍhŸh¶h M’hjËubhÎ)”}”(hX–consistency_policy This indicates how the array maintains consistency in case of unexpected shutdown. It can be: none Array has no redundancy information, e.g. raid0, linear. resync Full resync is performed and all redundancy is regenerated when the array is started after unclean shutdown. bitmap Resync assisted by a write-intent bitmap. journal For raid4/5/6, journal device is used to log transactions and replay after unclean shutdown. ppl For raid5 only, Partial Parity Log is used to close the write hole and eliminate resync. The accepted values when writing to this file are ``ppl`` and ``resync``, used to enable and disable PPL. ”h]”(hÔ)”}”(hŒconsistency_policy”h]”hŒconsistency_policy”…””}”(hjáhžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÓhŸh¶h M«hjÝubhä)”}”(hhh]”(hé)”}”(hŒ]This indicates how the array maintains consistency in case of unexpected shutdown. It can be:”h]”hŒ]This indicates how the array maintains consistency in case of unexpected shutdown. It can be:”…””}”(hjòhžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hèhŸh¶h M•hjïubhÉ)”}”(hhh]”(hÎ)”}”(hŒ>none Array has no redundancy information, e.g. raid0, linear. ”h]”(hÔ)”}”(hŒnone”h]”hŒnone”…””}”(hjhžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÓhŸh¶h M™hjubhä)”}”(hhh]”hé)”}”(hŒ8Array has no redundancy information, e.g. raid0, linear.”h]”hŒ8Array has no redundancy information, e.g. raid0, linear.”…””}”(hjhžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hèhŸh¶h M™hjubah}”(h]”h ]”h"]”h$]”h&]”uh1hãhjubeh}”(h]”h ]”h"]”h$]”h&]”uh1hÍhŸh¶h M™hjubhÎ)”}”(hŒtresync Full resync is performed and all redundancy is regenerated when the array is started after unclean shutdown. ”h]”(hÔ)”}”(hŒresync”h]”hŒresync”…””}”(hj6hžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÓhŸh¶h Mhj2ubhä)”}”(hhh]”hé)”}”(hŒlFull resync is performed and all redundancy is regenerated when the array is started after unclean shutdown.”h]”hŒlFull resync is performed and all redundancy is regenerated when the array is started after unclean shutdown.”…””}”(hjGhžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hèhŸh¶h MœhjDubah}”(h]”h ]”h"]”h$]”h&]”uh1hãhj2ubeh}”(h]”h ]”h"]”h$]”h&]”uh1hÍhŸh¶h MhjubhÎ)”}”(hŒ1bitmap Resync assisted by a write-intent bitmap. ”h]”(hÔ)”}”(hŒbitmap”h]”hŒbitmap”…””}”(hjehžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÓhŸh¶h M hjaubhä)”}”(hhh]”hé)”}”(hŒ)Resync assisted by a write-intent bitmap.”h]”hŒ)Resync assisted by a write-intent bitmap.”…””}”(hjvhžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hèhŸh¶h M hjsubah}”(h]”h ]”h"]”h$]”h&]”uh1hãhjaubeh}”(h]”h ]”h"]”h$]”h&]”uh1hÍhŸh¶h M hjubhÎ)”}”(hŒejournal For raid4/5/6, journal device is used to log transactions and replay after unclean shutdown. ”h]”(hÔ)”}”(hŒjournal”h]”hŒjournal”…””}”(hj”hžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÓhŸh¶h M¤hjubhä)”}”(hhh]”hé)”}”(hŒ\For raid4/5/6, journal device is used to log transactions and replay after unclean shutdown.”h]”hŒ\For raid4/5/6, journal device is used to log transactions and replay after unclean shutdown.”…””}”(hj¥hžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hèhŸh¶h M£hj¢ubah}”(h]”h ]”h"]”h$]”h&]”uh1hãhjubeh}”(h]”h ]”h"]”h$]”h&]”uh1hÍhŸh¶h M¤hjubhÎ)”}”(hŒ]ppl For raid5 only, Partial Parity Log is used to close the write hole and eliminate resync. ”h]”(hÔ)”}”(hŒppl”h]”hŒppl”…””}”(hjÃhžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÓhŸh¶h M¨hj¿ubhä)”}”(hhh]”hé)”}”(hŒXFor raid5 only, Partial Parity Log is used to close the write hole and eliminate resync.”h]”hŒXFor raid5 only, Partial Parity Log is used to close the write hole and eliminate resync.”…””}”(hjÔhžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hèhŸh¶h M§hjÑubah}”(h]”h ]”h"]”h$]”h&]”uh1hãhj¿ubeh}”(h]”h ]”h"]”h$]”h&]”uh1hÍhŸh¶h M¨hjubeh}”(h]”h ]”h"]”h$]”h&]”uh1hÈhjïubhé)”}”(hŒiThe accepted values when writing to this file are ``ppl`` and ``resync``, used to enable and disable PPL.”h]”(hŒ2The accepted values when writing to this file are ”…””}”(hjôhžhhŸNh Nubj„)”}”(hŒ``ppl``”h]”hŒppl”…””}”(hjühžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1jƒhjôubhŒ and ”…””}”(hjôhžhhŸNh Nubj„)”}”(hŒ ``resync``”h]”hŒresync”…””}”(hjhžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1jƒhjôubhŒ!, used to enable and disable PPL.”…””}”(hjôhžhhŸNh Nubeh}”(h]”h ]”h"]”h$]”h&]”uh1hèhŸh¶h Mªhjïubeh}”(h]”h ]”h"]”h$]”h&]”uh1hãhjÝubeh}”(h]”h ]”h"]”h$]”h&]”uh1hÍhŸh¶h M«hjËubhÎ)”}”(hŒiuuid This indicates the UUID of the array in the following format: xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx ”h]”(hÔ)”}”(hŒuuid”h]”hŒuuid”…””}”(hj6hžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÓhŸh¶h M°hj2ubhä)”}”(hhh]”hé)”}”(hŒbThis indicates the UUID of the array in the following format: xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx”h]”hŒbThis indicates the UUID of the array in the following format: xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx”…””}”(hjGhžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hèhŸh¶h M®hjDubah}”(h]”h ]”h"]”h$]”h&]”uh1hãhj2ubeh}”(h]”h ]”h"]”h$]”h&]”uh1hÍhŸh¶h M°hjËubeh}”(h]”h ]”h"]”h$]”h&]”uh1hÈhjÇubah}”(h]”h ]”h"]”h$]”h&]”uh1jÅhŸh¶h KÁhjFhžhubhé)”}”(hŒmAs component devices are added to an md array, they appear in the ``md`` directory as new directories named::”h]”(hŒBAs component devices are added to an md array, they appear in the ”…””}”(hjmhžhhŸNh Nubj„)”}”(hŒ``md``”h]”hŒmd”…””}”(hjuhžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1jƒhjmubhŒ$ directory as new directories named:”…””}”(hjmhžhhŸNh Nubeh}”(h]”h ]”h"]”h$]”h&]”uh1hèhŸh¶h M²hjFhžhubj3)”}”(hŒdev-XXX”h]”hŒdev-XXX”…””}”hjsbah}”(h]”h ]”h"]”h$]”h&]”jBjCuh1j2hŸh¶h MµhjFhžhubhé)”}”(hŒawhere ``XXX`` is a name that the kernel knows for the device, e.g. hdb1. Each directory contains:”h]”(hŒwhere ”…””}”(hj›hžhhŸNh Nubj„)”}”(hŒ``XXX``”h]”hŒXXX”…””}”(hj£hžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1jƒhj›ubhŒT is a name that the kernel knows for the device, e.g. hdb1. Each directory contains:”…””}”(hj›hžhhŸNh Nubeh}”(h]”h ]”h"]”h$]”h&]”uh1hèhŸh¶h M·hjFhžhubjÆ)”}”(hX/block a symlink to the block device in /sys/block, e.g.:: /sys/block/md0/md/dev-hdb1/block -> ../../../../block/hdb/hdb1 super A file containing an image of the superblock read from, or written to, that device. state A file recording the current state of the device in the array which can be a comma separated list of: faulty device has been kicked from active use due to a detected fault, or it has unacknowledged bad blocks in_sync device is a fully in-sync member of the array writemostly device will only be subject to read requests if there are no other options. This applies only to raid1 arrays. blocked device has failed, and the failure hasn't been acknowledged yet by the metadata handler. Writes that would write to this device if it were not faulty are blocked. spare device is working, but not a full member. This includes spares that are in the process of being recovered to write_error device has ever seen a write error. want_replacement device is (mostly) working but probably should be replaced, either due to errors or due to user request. replacement device is a replacement for another active device with same raid_disk. This list may grow in future. This can be written to. Writing ``faulty`` simulates a failure on the device. Writing ``remove`` removes the device from the array. Writing ``writemostly`` sets the writemostly flag. Writing ``-writemostly`` clears the writemostly flag. Writing ``blocked`` sets the ``blocked`` flag. Writing ``-blocked`` clears the ``blocked`` flags and allows writes to complete and possibly simulates an error. Writing ``in_sync`` sets the in_sync flag. Writing ``write_error`` sets writeerrorseen flag. Writing ``-write_error`` clears writeerrorseen flag. Writing ``want_replacement`` is allowed at any time except to a replacement device or a spare. It sets the flag. Writing ``-want_replacement`` is allowed at any time. It clears the flag. Writing ``replacement`` or ``-replacement`` is only allowed before starting the array. It sets or clears the flag. This file responds to select/poll. Any change to ``faulty`` or ``blocked`` causes an event. errors An approximate count of read errors that have been detected on this device but have not caused the device to be evicted from the array (either because they were corrected or because they happened while the array was read-only). When using version-1 metadata, this value persists across restarts of the array. This value can be written while assembling an array thus providing an ongoing count for arrays with metadata managed by userspace. slot This gives the role that the device has in the array. It will either be ``none`` if the device is not active in the array (i.e. is a spare or has failed) or an integer less than the ``raid_disks`` number for the array indicating which position it currently fills. This can only be set while assembling an array. A device for which this is set is assumed to be working. offset This gives the location in the device (in sectors from the start) where data from the array will be stored. Any part of the device before this offset is not touched, unless it is used for storing metadata (Formats 1.1 and 1.2). size The amount of the device, after the offset, that can be used for storage of data. This will normally be the same as the component_size. This can be written while assembling an array. If a value less than the current component_size is written, it will be rejected. recovery_start When the device is not ``in_sync``, this records the number of sectors from the start of the device which are known to be correct. This is normally zero, but during a recovery operation it will steadily increase, and if the recovery is interrupted, restoring this value can cause recovery to avoid repeating the earlier blocks. With v1.x metadata, this value is saved and restored automatically. This can be set whenever the device is not an active member of the array, either before the array is activated, or before the ``slot`` is set. Setting this to ``none`` is equivalent to setting ``in_sync``. Setting to any other value also clears the ``in_sync`` flag. bad_blocks This gives the list of all known bad blocks in the form of start address and length (in sectors respectively). If output is too big to fit in a page, it will be truncated. Writing ``sector length`` to this file adds new acknowledged (i.e. recorded to disk safely) bad blocks. unacknowledged_bad_blocks This gives the list of known-but-not-yet-saved-to-disk bad blocks in the same form of ``bad_blocks``. If output is too big to fit in a page, it will be truncated. Writing to this file adds bad blocks without acknowledging them. This is largely for testing. ppl_sector, ppl_size Location and size (in sectors) of the space used for Partial Parity Log on this device. ”h]”hÉ)”}”(hhh]”(hÎ)”}”(hŒblock a symlink to the block device in /sys/block, e.g.:: /sys/block/md0/md/dev-hdb1/block -> ../../../../block/hdb/hdb1 ”h]”(hÔ)”}”(hŒblock”h]”hŒblock”…””}”(hjÆhžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÓhŸh¶h M½hjÂubhä)”}”(hhh]”(hé)”}”(hŒ3a symlink to the block device in /sys/block, e.g.::”h]”hŒ2a symlink to the block device in /sys/block, e.g.:”…””}”(hj×hžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hèhŸh¶h M»hjÔubj3)”}”(hŒ>/sys/block/md0/md/dev-hdb1/block -> ../../../../block/hdb/hdb1”h]”hŒ>/sys/block/md0/md/dev-hdb1/block -> ../../../../block/hdb/hdb1”…””}”hjåsbah}”(h]”h ]”h"]”h$]”h&]”jBjCuh1j2hŸh¶h M½hjÔubeh}”(h]”h ]”h"]”h$]”h&]”uh1hãhjÂubeh}”(h]”h ]”h"]”h$]”h&]”uh1hÍhŸh¶h M½hj¿ubhÎ)”}”(hŒZsuper A file containing an image of the superblock read from, or written to, that device. ”h]”(hÔ)”}”(hŒsuper”h]”hŒsuper”…””}”(hjhžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÓhŸh¶h MÁhjÿubhä)”}”(hhh]”hé)”}”(hŒSA file containing an image of the superblock read from, or written to, that device.”h]”hŒSA file containing an image of the superblock read from, or written to, that device.”…””}”(hjhžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hèhŸh¶h MÀhjubah}”(h]”h ]”h"]”h$]”h&]”uh1hãhjÿubeh}”(h]”h ]”h"]”h$]”h&]”uh1hÍhŸh¶h MÁhj¿ubhÎ)”}”(hXústate A file recording the current state of the device in the array which can be a comma separated list of: faulty device has been kicked from active use due to a detected fault, or it has unacknowledged bad blocks in_sync device is a fully in-sync member of the array writemostly device will only be subject to read requests if there are no other options. This applies only to raid1 arrays. blocked device has failed, and the failure hasn't been acknowledged yet by the metadata handler. Writes that would write to this device if it were not faulty are blocked. spare device is working, but not a full member. This includes spares that are in the process of being recovered to write_error device has ever seen a write error. want_replacement device is (mostly) working but probably should be replaced, either due to errors or due to user request. replacement device is a replacement for another active device with same raid_disk. This list may grow in future. This can be written to. Writing ``faulty`` simulates a failure on the device. Writing ``remove`` removes the device from the array. Writing ``writemostly`` sets the writemostly flag. Writing ``-writemostly`` clears the writemostly flag. Writing ``blocked`` sets the ``blocked`` flag. Writing ``-blocked`` clears the ``blocked`` flags and allows writes to complete and possibly simulates an error. Writing ``in_sync`` sets the in_sync flag. Writing ``write_error`` sets writeerrorseen flag. Writing ``-write_error`` clears writeerrorseen flag. Writing ``want_replacement`` is allowed at any time except to a replacement device or a spare. It sets the flag. Writing ``-want_replacement`` is allowed at any time. It clears the flag. Writing ``replacement`` or ``-replacement`` is only allowed before starting the array. It sets or clears the flag. This file responds to select/poll. Any change to ``faulty`` or ``blocked`` causes an event. ”h]”(hÔ)”}”(hŒstate”h]”hŒstate”…””}”(hj2hžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÓhŸh¶h Mhj.ubhä)”}”(hhh]”(hé)”}”(hŒeA file recording the current state of the device in the array which can be a comma separated list of:”h]”hŒeA file recording the current state of the device in the array which can be a comma separated list of:”…””}”(hjChžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hèhŸh¶h MÄhj@ubjÆ)”}”(hX faulty device has been kicked from active use due to a detected fault, or it has unacknowledged bad blocks in_sync device is a fully in-sync member of the array writemostly device will only be subject to read requests if there are no other options. This applies only to raid1 arrays. blocked device has failed, and the failure hasn't been acknowledged yet by the metadata handler. Writes that would write to this device if it were not faulty are blocked. spare device is working, but not a full member. This includes spares that are in the process of being recovered to write_error device has ever seen a write error. want_replacement device is (mostly) working but probably should be replaced, either due to errors or due to user request. replacement device is a replacement for another active device with same raid_disk. ”h]”hÉ)”}”(hhh]”(hÎ)”}”(hŒkfaulty device has been kicked from active use due to a detected fault, or it has unacknowledged bad blocks ”h]”(hÔ)”}”(hŒfaulty”h]”hŒfaulty”…””}”(hj\hžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÓhŸh¶h MÊhjXubhä)”}”(hhh]”hé)”}”(hŒcdevice has been kicked from active use due to a detected fault, or it has unacknowledged bad blocks”h]”hŒcdevice has been kicked from active use due to a detected fault, or it has unacknowledged bad blocks”…””}”(hjmhžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hèhŸh¶h MÈhjjubah}”(h]”h ]”h"]”h$]”h&]”uh1hãhjXubeh}”(h]”h ]”h"]”h$]”h&]”uh1hÍhŸh¶h MÊhjUubhÎ)”}”(hŒ6in_sync device is a fully in-sync member of the array ”h]”(hÔ)”}”(hŒin_sync”h]”hŒin_sync”…””}”(hj‹hžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÓhŸh¶h MÍhj‡ubhä)”}”(hhh]”hé)”}”(hŒ-device is a fully in-sync member of the array”h]”hŒ-device is a fully in-sync member of the array”…””}”(hjœhžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hèhŸh¶h MÍhj™ubah}”(h]”h ]”h"]”h$]”h&]”uh1hãhj‡ubeh}”(h]”h ]”h"]”h$]”h&]”uh1hÍhŸh¶h MÍhjUubhÎ)”}”(hŒ|writemostly device will only be subject to read requests if there are no other options. This applies only to raid1 arrays. ”h]”(hÔ)”}”(hŒwritemostly”h]”hŒwritemostly”…””}”(hjºhžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÓhŸh¶h MÓhj¶ubhä)”}”(hhh]”(hé)”}”(hŒKdevice will only be subject to read requests if there are no other options.”h]”hŒKdevice will only be subject to read requests if there are no other options.”…””}”(hjËhžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hèhŸh¶h MÐhjÈubhé)”}”(hŒ"This applies only to raid1 arrays.”h]”hŒ"This applies only to raid1 arrays.”…””}”(hjÙhžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hèhŸh¶h MÓhjÈubeh}”(h]”h ]”h"]”h$]”h&]”uh1hãhj¶ubeh}”(h]”h ]”h"]”h$]”h&]”uh1hÍhŸh¶h MÓhjUubhÎ)”}”(hŒ¬blocked device has failed, and the failure hasn't been acknowledged yet by the metadata handler. Writes that would write to this device if it were not faulty are blocked. ”h]”(hÔ)”}”(hŒblocked”h]”hŒblocked”…””}”(hj÷hžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÓhŸh¶h MÚhjóubhä)”}”(hhh]”(hé)”}”(hŒXdevice has failed, and the failure hasn't been acknowledged yet by the metadata handler.”h]”hŒZdevice has failed, and the failure hasnâ€™t been acknowledged yet by the metadata handler.”…””}”(hjhžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hèhŸh¶h MÖhjubhé)”}”(hŒIWrites that would write to this device if it were not faulty are blocked.”h]”hŒIWrites that would write to this device if it were not faulty are blocked.”…””}”(hjhžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hèhŸh¶h MÙhjubeh}”(h]”h ]”h"]”h$]”h&]”uh1hãhjóubeh}”(h]”h ]”h"]”h$]”h&]”uh1hÍhŸh¶h MÚhjUubhÎ)”}”(hŒtspare device is working, but not a full member. This includes spares that are in the process of being recovered to ”h]”(hÔ)”}”(hŒspare”h]”hŒspare”…””}”(hj4hžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÓhŸh¶h Màhj0ubhä)”}”(hhh]”(hé)”}”(hŒ)device is working, but not a full member.”h]”hŒ)device is working, but not a full member.”…””}”(hjEhžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hèhŸh¶h MÝhjBubhé)”}”(hŒBThis includes spares that are in the process of being recovered to”h]”hŒBThis includes spares that are in the process of being recovered to”…””}”(hjShžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hèhŸh¶h MßhjBubeh}”(h]”h ]”h"]”h$]”h&]”uh1hãhj0ubeh}”(h]”h ]”h"]”h$]”h&]”uh1hÍhŸh¶h MàhjUubhÎ)”}”(hŒ0write_error device has ever seen a write error. ”h]”(hÔ)”}”(hŒwrite_error”h]”hŒwrite_error”…””}”(hjqhžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÓhŸh¶h Mãhjmubhä)”}”(hhh]”hé)”}”(hŒ#device has ever seen a write error.”h]”hŒ#device has ever seen a write error.”…””}”(hj‚hžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hèhŸh¶h Mãhjubah}”(h]”h ]”h"]”h$]”h&]”uh1hãhjmubeh}”(h]”h ]”h"]”h$]”h&]”uh1hÍhŸh¶h MãhjUubhÎ)”}”(hŒzwant_replacement device is (mostly) working but probably should be replaced, either due to errors or due to user request. ”h]”(hÔ)”}”(hŒwant_replacement”h]”hŒwant_replacement”…””}”(hj hžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÓhŸh¶h Mèhjœubhä)”}”(hhh]”hé)”}”(hŒhdevice is (mostly) working but probably should be replaced, either due to errors or due to user request.”h]”hŒhdevice is (mostly) working but probably should be replaced, either due to errors or due to user request.”…””}”(hj±hžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hèhŸh¶h Mæhj®ubah}”(h]”h ]”h"]”h$]”h&]”uh1hãhjœubeh}”(h]”h ]”h"]”h$]”h&]”uh1hÍhŸh¶h MèhjUubhÎ)”}”(hŒTreplacement device is a replacement for another active device with same raid_disk. ”h]”(hÔ)”}”(hŒreplacement”h]”hŒreplacement”…””}”(hjÏhžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÓhŸh¶h MíhjËubhä)”}”(hhh]”hé)”}”(hŒFdevice is a replacement for another active device with same raid_disk.”h]”hŒFdevice is a replacement for another active device with same raid_disk.”…””}”(hjàhžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hèhŸh¶h MëhjÝubah}”(h]”h ]”h"]”h$]”h&]”uh1hãhjËubeh}”(h]”h ]”h"]”h$]”h&]”uh1hÍhŸh¶h MíhjUubeh}”(h]”h ]”h"]”h$]”h&]”uh1hÈhjQubah}”(h]”h ]”h"]”h$]”h&]”uh1jÅhŸh¶h MÇhj@ubhé)”}”(hŒThis list may grow in future.”h]”hŒThis list may grow in future.”…””}”(hjhžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hèhŸh¶h Mïhj@ubhé)”}”(hŒThis can be written to.”h]”hŒThis can be written to.”…””}”(hjhžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hèhŸh¶h Mñhj@ubhé)”}”(hŒ6Writing ``faulty`` simulates a failure on the device.”h]”(hŒWriting ”…””}”(hj"hžhhŸNh Nubj„)”}”(hŒ ``faulty``”h]”hŒfaulty”…””}”(hj*hžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1jƒhj"ubhŒ$ simulates a failure on the device.”…””}”(hj"hžhhŸNh Nubeh}”(h]”h ]”h"]”h$]”h&]”uh1hèhŸh¶h Móhj@ubhé)”}”(hŒ5Writing ``remove`` removes the device from the array.”h]”(hŒWriting ”…””}”(hjBhžhhŸNh Nubj„)”}”(hŒ ``remove``”h]”hŒremove”…””}”(hjJhžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1jƒhjBubhŒ# removes the device from the array.”…””}”(hjBhžhhŸNh Nubeh}”(h]”h ]”h"]”h$]”h&]”uh1hèhŸh¶h Mõhj@ubhé)”}”(hŒ2Writing ``writemostly`` sets the writemostly flag.”h]”(hŒWriting ”…””}”(hjbhžhhŸNh Nubj„)”}”(hŒ``writemostly``”h]”hŒwritemostly”…””}”(hjjhžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1jƒhjbubhŒ sets the writemostly flag.”…””}”(hjbhžhhŸNh Nubeh}”(h]”h ]”h"]”h$]”h&]”uh1hèhŸh¶h M÷hj@ubhé)”}”(hŒ5Writing ``-writemostly`` clears the writemostly flag.”h]”(hŒWriting ”…””}”(hj‚hžhhŸNh Nubj„)”}”(hŒ``-writemostly``”h]”hŒ-writemostly”…””}”(hjŠhžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1jƒhj‚ubhŒ clears the writemostly flag.”…””}”(hj‚hžhhŸNh Nubeh}”(h]”h ]”h"]”h$]”h&]”uh1hèhŸh¶h Mùhj@ubhé)”}”(hŒ.Writing ``blocked`` sets the ``blocked`` flag.”h]”(hŒWriting ”…””}”(hj¢hžhhŸNh Nubj„)”}”(hŒ``blocked``”h]”hŒblocked”…””}”(hjªhžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1jƒhj¢ubhŒ sets the ”…””}”(hj¢hžhhŸNh Nubj„)”}”(hŒ``blocked``”h]”hŒblocked”…””}”(hj¼hžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1jƒhj¢ubhŒ flag.”…””}”(hj¢hžhhŸNh Nubeh}”(h]”h ]”h"]”h$]”h&]”uh1hèhŸh¶h Mûhj@ubhé)”}”(hŒpWriting ``-blocked`` clears the ``blocked`` flags and allows writes to complete and possibly simulates an error.”h]”(hŒWriting ”…””}”(hjÔhžhhŸNh Nubj„)”}”(hŒ``-blocked``”h]”hŒ-blocked”…””}”(hjÜhžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1jƒhjÔubhŒ clears the ”…””}”(hjÔhžhhŸNh Nubj„)”}”(hŒ``blocked``”h]”hŒblocked”…””}”(hjîhžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1jƒhjÔubhŒE flags and allows writes to complete and possibly simulates an error.”…””}”(hjÔhžhhŸNh Nubeh}”(h]”h ]”h"]”h$]”h&]”uh1hèhŸh¶h Mýhj@ubhé)”}”(hŒ*Writing ``in_sync`` sets the in_sync flag.”h]”(hŒWriting ”…””}”(hjhžhhŸNh Nubj„)”}”(hŒ``in_sync``”h]”hŒin_sync”…””}”(hjhžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1jƒhjubhŒ sets the in_sync flag.”…””}”(hjhžhhŸNh Nubeh}”(h]”h ]”h"]”h$]”h&]”uh1hèhŸh¶h Mhj@ubhé)”}”(hŒ1Writing ``write_error`` sets writeerrorseen flag.”h]”(hŒWriting ”…””}”(hj&hžhhŸNh Nubj„)”}”(hŒ``write_error``”h]”hŒwrite_error”…””}”(hj.hžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1jƒhj&ubhŒ sets writeerrorseen flag.”…””}”(hj&hžhhŸNh Nubeh}”(h]”h ]”h"]”h$]”h&]”uh1hèhŸh¶h Mhj@ubhé)”}”(hŒ4Writing ``-write_error`` clears writeerrorseen flag.”h]”(hŒWriting ”…””}”(hjFhžhhŸNh Nubj„)”}”(hŒ``-write_error``”h]”hŒ-write_error”…””}”(hjNhžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1jƒhjFubhŒ clears writeerrorseen flag.”…””}”(hjFhžhhŸNh Nubeh}”(h]”h ]”h"]”h$]”h&]”uh1hèhŸh¶h Mhj@ubhé)”}”(hŒqWriting ``want_replacement`` is allowed at any time except to a replacement device or a spare. It sets the flag.”h]”(hŒWriting ”…””}”(hjfhžhhŸNh Nubj„)”}”(hŒ``want_replacement``”h]”hŒwant_replacement”…””}”(hjnhžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1jƒhjfubhŒU is allowed at any time except to a replacement device or a spare. It sets the flag.”…””}”(hjfhžhhŸNh Nubeh}”(h]”h ]”h"]”h$]”h&]”uh1hèhŸh¶h Mhj@ubhé)”}”(hŒJWriting ``-want_replacement`` is allowed at any time. It clears the flag.”h]”(hŒWriting ”…””}”(hj†hžhhŸNh Nubj„)”}”(hŒ``-want_replacement``”h]”hŒ-want_replacement”…””}”(hjŽhžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1jƒhj†ubhŒ- is allowed at any time. It clears the flag.”…””}”(hj†hžhhŸNh Nubeh}”(h]”h ]”h"]”h$]”h&]”uh1hèhŸh¶h M hj@ubhé)”}”(hŒsWriting ``replacement`` or ``-replacement`` is only allowed before starting the array. It sets or clears the flag.”h]”(hŒWriting ”…””}”(hj¦hžhhŸNh Nubj„)”}”(hŒ``replacement``”h]”hŒreplacement”…””}”(hj®hžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1jƒhj¦ubhŒ or ”…””}”(hj¦hžhhŸNh Nubj„)”}”(hŒ``-replacement``”h]”hŒ-replacement”…””}”(hjÀhžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1jƒhj¦ubhŒH is only allowed before starting the array. It sets or clears the flag.”…””}”(hj¦hžhhŸNh Nubeh}”(h]”h ]”h"]”h$]”h&]”uh1hèhŸh¶h Mhj@ubhé)”}”(hŒ[This file responds to select/poll. Any change to ``faulty`` or ``blocked`` causes an event.”h]”(hŒ1This file responds to select/poll. Any change to ”…””}”(hjØhžhhŸNh Nubj„)”}”(hŒ ``faulty``”h]”hŒfaulty”…””}”(hjàhžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1jƒhjØubhŒ or ”…””}”(hjØhžhhŸNh Nubj„)”}”(hŒ``blocked``”h]”hŒblocked”…””}”(hjòhžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1jƒhjØubhŒ causes an event.”…””}”(hjØhžhhŸNh Nubeh}”(h]”h ]”h"]”h$]”h&]”uh1hèhŸh¶h Mhj@ubeh}”(h]”h ]”h"]”h$]”h&]”uh1hãhj.ubeh}”(h]”h ]”h"]”h$]”h&]”uh1hÍhŸh¶h Mhj¿ubhÎ)”}”(hXÁerrors An approximate count of read errors that have been detected on this device but have not caused the device to be evicted from the array (either because they were corrected or because they happened while the array was read-only). When using version-1 metadata, this value persists across restarts of the array. This value can be written while assembling an array thus providing an ongoing count for arrays with metadata managed by userspace. ”h]”(hÔ)”}”(hŒerrors”h]”hŒerrors”…””}”(hjhžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÓhŸh¶h Mhjubhä)”}”(hhh]”(hé)”}”(hX5An approximate count of read errors that have been detected on this device but have not caused the device to be evicted from the array (either because they were corrected or because they happened while the array was read-only). When using version-1 metadata, this value persists across restarts of the array.”h]”hX5An approximate count of read errors that have been detected on this device but have not caused the device to be evicted from the array (either because they were corrected or because they happened while the array was read-only). When using version-1 metadata, this value persists across restarts of the array.”…””}”(hj+hžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hèhŸh¶h Mhj(ubhé)”}”(hŒ‚This value can be written while assembling an array thus providing an ongoing count for arrays with metadata managed by userspace.”h]”hŒ‚This value can be written while assembling an array thus providing an ongoing count for arrays with metadata managed by userspace.”…””}”(hj9hžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hèhŸh¶h Mhj(ubeh}”(h]”h ]”h"]”h$]”h&]”uh1hãhjubeh}”(h]”h ]”h"]”h$]”h&]”uh1hÍhŸh¶h Mhj¿ubhÎ)”}”(hXyslot This gives the role that the device has in the array. It will either be ``none`` if the device is not active in the array (i.e. is a spare or has failed) or an integer less than the ``raid_disks`` number for the array indicating which position it currently fills. This can only be set while assembling an array. A device for which this is set is assumed to be working. ”h]”(hÔ)”}”(hŒslot”h]”hŒslot”…””}”(hjWhžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÓhŸh¶h M$hjSubhä)”}”(hhh]”hé)”}”(hXsThis gives the role that the device has in the array. It will either be ``none`` if the device is not active in the array (i.e. is a spare or has failed) or an integer less than the ``raid_disks`` number for the array indicating which position it currently fills. This can only be set while assembling an array. A device for which this is set is assumed to be working.”h]”(hŒIThis gives the role that the device has in the array. It will either be ”…””}”(hjhhžhhŸNh Nubj„)”}”(hŒ``none``”h]”hŒnone”…””}”(hjphžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1jƒhjhubhŒf if the device is not active in the array (i.e. is a spare or has failed) or an integer less than the ”…””}”(hjhhžhhŸNh Nubj„)”}”(hŒ``raid_disks``”h]”hŒ raid_disks”…””}”(hj‚hžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1jƒhjhubhŒ® number for the array indicating which position it currently fills. This can only be set while assembling an array. A device for which this is set is assumed to be working.”…””}”(hjhhžhhŸNh Nubeh}”(h]”h ]”h"]”h$]”h&]”uh1hèhŸh¶h Mhjeubah}”(h]”h ]”h"]”h$]”h&]”uh1hãhjSubeh}”(h]”h ]”h"]”h$]”h&]”uh1hÍhŸh¶h M$hj¿ubhÎ)”}”(hŒìoffset This gives the location in the device (in sectors from the start) where data from the array will be stored. Any part of the device before this offset is not touched, unless it is used for storing metadata (Formats 1.1 and 1.2). ”h]”(hÔ)”}”(hŒoffset”h]”hŒoffset”…””}”(hjªhžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÓhŸh¶h M*hj¦ubhä)”}”(hhh]”hé)”}”(hŒäThis gives the location in the device (in sectors from the start) where data from the array will be stored. Any part of the device before this offset is not touched, unless it is used for storing metadata (Formats 1.1 and 1.2).”h]”hŒäThis gives the location in the device (in sectors from the start) where data from the array will be stored. Any part of the device before this offset is not touched, unless it is used for storing metadata (Formats 1.1 and 1.2).”…””}”(hj»hžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hèhŸh¶h M'hj¸ubah}”(h]”h ]”h"]”h$]”h&]”uh1hãhj¦ubeh}”(h]”h ]”h"]”h$]”h&]”uh1hÍhŸh¶h M*hj¿ubhÎ)”}”(hXsize The amount of the device, after the offset, that can be used for storage of data. This will normally be the same as the component_size. This can be written while assembling an array. If a value less than the current component_size is written, it will be rejected. ”h]”(hÔ)”}”(hŒsize”h]”hŒsize”…””}”(hjÙhžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÓhŸh¶h M1hjÕubhä)”}”(hhh]”hé)”}”(hX The amount of the device, after the offset, that can be used for storage of data. This will normally be the same as the component_size. This can be written while assembling an array. If a value less than the current component_size is written, it will be rejected.”h]”hX The amount of the device, after the offset, that can be used for storage of data. This will normally be the same as the component_size. This can be written while assembling an array. If a value less than the current component_size is written, it will be rejected.”…””}”(hjêhžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hèhŸh¶h M-hjçubah}”(h]”h ]”h"]”h$]”h&]”uh1hãhjÕubeh}”(h]”h ]”h"]”h$]”h&]”uh1hÍhŸh¶h M1hj¿ubhÎ)”}”(hXªrecovery_start When the device is not ``in_sync``, this records the number of sectors from the start of the device which are known to be correct. This is normally zero, but during a recovery operation it will steadily increase, and if the recovery is interrupted, restoring this value can cause recovery to avoid repeating the earlier blocks. With v1.x metadata, this value is saved and restored automatically. This can be set whenever the device is not an active member of the array, either before the array is activated, or before the ``slot`` is set. Setting this to ``none`` is equivalent to setting ``in_sync``. Setting to any other value also clears the ``in_sync`` flag. ”h]”(hÔ)”}”(hŒrecovery_start”h]”hŒrecovery_start”…””}”(hjhžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÓhŸh¶h MAhjubhä)”}”(hhh]”(hé)”}”(hXWhen the device is not ``in_sync``, this records the number of sectors from the start of the device which are known to be correct. This is normally zero, but during a recovery operation it will steadily increase, and if the recovery is interrupted, restoring this value can cause recovery to avoid repeating the earlier blocks. With v1.x metadata, this value is saved and restored automatically.”h]”(hŒWhen the device is not ”…””}”(hjhžhhŸNh Nubj„)”}”(hŒ``in_sync``”h]”hŒin_sync”…””}”(hj!hžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1jƒhjubhXk, this records the number of sectors from the start of the device which are known to be correct. This is normally zero, but during a recovery operation it will steadily increase, and if the recovery is interrupted, restoring this value can cause recovery to avoid repeating the earlier blocks. With v1.x metadata, this value is saved and restored automatically.”…””}”(hjhžhhŸNh Nubeh}”(h]”h ]”h"]”h$]”h&]”uh1hèhŸh¶h M4hjubhé)”}”(hŒŽThis can be set whenever the device is not an active member of the array, either before the array is activated, or before the ``slot`` is set.”h]”(hŒ~This can be set whenever the device is not an active member of the array, either before the array is activated, or before the ”…””}”(hj9hžhhŸNh Nubj„)”}”(hŒ``slot``”h]”hŒslot”…””}”(hjAhžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1jƒhj9ubhŒ is set.”…””}”(hj9hžhhŸNh Nubeh}”(h]”h ]”h"]”h$]”h&]”uh1hèhŸh¶h M