€•ŒŒsphinx.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/iostats”Œmodname”NŒ classname”NŒrefexplicit”ˆuŒtagname”hhhubh)”}”(hhh]”hŒChinese (Traditional)”…””}”hh2sbah}”(h]”h ]”h"]”h$]”h&]”Œ refdomain”h)Œreftype”h+Œ reftarget”Œ'/translations/zh_TW/admin-guide/iostats”Œmodname”NŒ classname”NŒrefexplicit”ˆuh1hhhubh)”}”(hhh]”hŒItalian”…””}”hhFsbah}”(h]”h ]”h"]”h$]”h&]”Œ refdomain”h)Œreftype”h+Œ reftarget”Œ'/translations/it_IT/admin-guide/iostats”Œmodname”NŒ classname”NŒrefexplicit”ˆuh1hhhubh)”}”(hhh]”hŒJapanese”…””}”hhZsbah}”(h]”h ]”h"]”h$]”h&]”Œ refdomain”h)Œreftype”h+Œ reftarget”Œ'/translations/ja_JP/admin-guide/iostats”Œmodname”NŒ classname”NŒrefexplicit”ˆuh1hhhubh)”}”(hhh]”hŒKorean”…””}”hhnsbah}”(h]”h ]”h"]”h$]”h&]”Œ refdomain”h)Œreftype”h+Œ reftarget”Œ'/translations/ko_KR/admin-guide/iostats”Œmodname”NŒ classname”NŒrefexplicit”ˆuh1hhhubh)”}”(hhh]”hŒSpanish”…””}”hh‚sbah}”(h]”h ]”h"]”h$]”h&]”Œ refdomain”h)Œreftype”h+Œ reftarget”Œ'/translations/sp_SP/admin-guide/iostats”Œmodname”NŒ classname”NŒrefexplicit”ˆuh1hhhubeh}”(h]”h ]”h"]”h$]”h&]”Œcurrent_language”ŒEnglish”uh1h hhŒ _document”hŒsource”NŒline”NubhŒsection”“”)”}”(hhh]”(hŒtitle”“”)”}”(hŒI/O statistics fields”h]”hŒI/O statistics fields”…””}”(hh¨hžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1h¦hh£hžhhŸŒA/var/lib/git/docbuild/linux/Documentation/admin-guide/iostats.rst”h KubhŒ paragraph”“”)”}”(hŒ§The kernel exposes disk statistics via ``/proc/diskstats`` and ``/sys/block//stat``. These stats are usually accessed via tools such as ``sar`` and ``iostat``.”h]”(hŒ'The kernel exposes disk statistics via ”…””}”(hh¹hžhhŸNh NubhŒliteral”“”)”}”(hŒ``/proc/diskstats``”h]”hŒ/proc/diskstats”…””}”(hhÃhžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÁhh¹ubhŒ and ”…””}”(hh¹hžhhŸNh NubhÂ)”}”(hŒ``/sys/block//stat``”h]”hŒ/sys/block//stat”…””}”(hhÕhžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÁhh¹ubhŒ5. These stats are usually accessed via tools such as ”…””}”(hh¹hžhhŸNh NubhÂ)”}”(hŒ``sar``”h]”hŒsar”…””}”(hhçhžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÁhh¹ubhŒ and ”…””}”(hh¹hžhhŸNh NubhÂ)”}”(hŒ ``iostat``”h]”hŒiostat”…””}”(hhùhžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÁhh¹ubhŒ.”…””}”(hh¹hžhhŸNh Nubeh}”(h]”h ]”h"]”h$]”h&]”uh1h·hŸh¶h Khh£hžhubh¸)”}”(hŒ4Here are examples using a disk with two partitions::”h]”hŒ3Here are examples using a disk with two partitions:”…””}”(hjhžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1h·hŸh¶h K hh£hžhubhŒ literal_block”“”)”}”(hX/proc/diskstats: 259 0 nvme0n1 255999 814 12369153 47919 996852 81 36123024 425995 0 301795 580470 0 0 0 0 60602 106555 259 1 nvme0n1p1 492 813 17572 96 848 81 108288 210 0 76 307 0 0 0 0 0 0 259 2 nvme0n1p2 255401 1 12343477 47799 996004 0 36014736 425784 0 344336 473584 0 0 0 0 0 0 /sys/block/nvme0n1/stat: 255999 814 12369153 47919 996858 81 36123056 426009 0 301809 580491 0 0 0 0 60605 106562 /sys/block/nvme0n1/nvme0n1p1/stat: 492 813 17572 96 848 81 108288 210 0 76 307 0 0 0 0 0 0”h]”hX/proc/diskstats: 259 0 nvme0n1 255999 814 12369153 47919 996852 81 36123024 425995 0 301795 580470 0 0 0 0 60602 106555 259 1 nvme0n1p1 492 813 17572 96 848 81 108288 210 0 76 307 0 0 0 0 0 0 259 2 nvme0n1p2 255401 1 12343477 47799 996004 0 36014736 425784 0 344336 473584 0 0 0 0 0 0 /sys/block/nvme0n1/stat: 255999 814 12369153 47919 996858 81 36123056 426009 0 301809 580491 0 0 0 0 60605 106562 /sys/block/nvme0n1/nvme0n1p1/stat: 492 813 17572 96 848 81 108288 210 0 76 307 0 0 0 0 0 0”…””}”hj!sbah}”(h]”h ]”h"]”h$]”h&]”Œ xml:space”Œpreserve”uh1jhŸh¶h Khh£hžhubh¸)”}”(hX-Both files contain the same 17 statistics. ``/sys/block//stat`` contains the fields for ````. In ``/proc/diskstats`` the fields are prefixed with the major and minor device numbers and the device name. In the example above, the first stat value for ``nvme0n1`` is 255999 in both files.”h]”(hŒ+Both files contain the same 17 statistics. ”…””}”(hj1hžhhŸNh NubhÂ)”}”(hŒ``/sys/block//stat``”h]”hŒ/sys/block//stat”…””}”(hj9hžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÁhj1ubhŒ contains the fields for ”…””}”(hj1hžhhŸNh NubhÂ)”}”(hŒ````”h]”hŒ”…””}”(hjKhžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÁhj1ubhŒ. In ”…””}”(hj1hžhhŸNh NubhÂ)”}”(hŒ``/proc/diskstats``”h]”hŒ/proc/diskstats”…””}”(hj]hžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÁhj1ubhŒ… the fields are prefixed with the major and minor device numbers and the device name. In the example above, the first stat value for ”…””}”(hj1hžhhŸNh NubhÂ)”}”(hŒ``nvme0n1``”h]”hŒnvme0n1”…””}”(hjohžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÁhj1ubhŒ is 255999 in both files.”…””}”(hj1hžhhŸNh Nubeh}”(h]”h ]”h"]”h$]”h&]”uh1h·hŸh¶h Khh£hžhubh¸)”}”(hXThe sysfs ``stat`` file is efficient for monitoring a small, known set of disks. If you're tracking a large number of devices, ``/proc/diskstats`` is often the better choice since it avoids the overhead of opening and closing multiple files for each snapshot.”h]”(hŒ The sysfs ”…””}”(hj‡hžhhŸNh NubhÂ)”}”(hŒ``stat``”h]”hŒstat”…””}”(hjhžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÁhj‡ubhŒo file is efficient for monitoring a small, known set of disks. If youâ€™re tracking a large number of devices, ”…””}”(hj‡hžhhŸNh NubhÂ)”}”(hŒ``/proc/diskstats``”h]”hŒ/proc/diskstats”…””}”(hj¡hžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÁhj‡ubhŒq is often the better choice since it avoids the overhead of opening and closing multiple files for each snapshot.”…””}”(hj‡hžhhŸNh Nubeh}”(h]”h ]”h"]”h$]”h&]”uh1h·hŸh¶h Khh£hžhubh¸)”}”(hXFAll fields are cumulative, monotonic counters, except for field 9, which resets to zero as I/Os complete. The remaining fields reset at boot, on device reattachment or reinitialization, or when the underlying counter overflows. Applications reading these counters should detect and handle resets when comparing stat snapshots.”h]”hXFAll fields are cumulative, monotonic counters, except for field 9, which resets to zero as I/Os complete. The remaining fields reset at boot, on device reattachment or reinitialization, or when the underlying counter overflows. Applications reading these counters should detect and handle resets when comparing stat snapshots.”…””}”(hj¹hžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1h·hŸh¶h K!hh£hžhubh¸)”}”(hŒŽEach set of stats only applies to the indicated device; if you want system-wide stats you'll have to find all the devices and sum them all up.”h]”hŒEach set of stats only applies to the indicated device; if you want system-wide stats youâ€™ll have to find all the devices and sum them all up.”…””}”(hjÇhžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1h·hŸh¶h K'hh£hžhubhŒdefinition_list”“”)”}”(hhh]”(hŒdefinition_list_item”“”)”}”(hŒkField 1 -- # of reads completed (unsigned long) This is the total number of reads completed successfully. ”h]”(hŒterm”“”)”}”(hŒ0Field 1 -- # of reads completed (unsigned long)”h]”hŒ0Field 1 -- # of reads completed (unsigned long)”…””}”(hjâhžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1jàhŸh¶h K+hjÜubhŒ definition”“”)”}”(hhh]”h¸)”}”(hŒ9This is the total number of reads completed successfully.”h]”hŒ9This is the total number of reads completed successfully.”…””}”(hjõhžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1h·hŸh¶h K+hjòubah}”(h]”h ]”h"]”h$]”h&]”uh1jðhjÜubeh}”(h]”h ]”h"]”h$]”h&]”uh1jÚhŸh¶h K+hj×ubjÛ)”}”(hX^Field 2 -- # of reads merged, field 6 -- # of writes merged (unsigned long) Reads and writes which are adjacent to each other may be merged for efficiency. Thus two 4K reads may become one 8K read before it is ultimately handed to the disk, and so it will be counted (and queued) as only one I/O. This field lets you know how often this was done. ”h]”(já)”}”(hŒLField 2 -- # of reads merged, field 6 -- # of writes merged (unsigned long)”h]”hŒLField 2 -- # of reads merged, field 6 -- # of writes merged (unsigned long)”…””}”(hjhžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1jàhŸh¶h K1hjubjñ)”}”(hhh]”h¸)”}”(hXReads and writes which are adjacent to each other may be merged for efficiency. Thus two 4K reads may become one 8K read before it is ultimately handed to the disk, and so it will be counted (and queued) as only one I/O. This field lets you know how often this was done.”h]”hXReads and writes which are adjacent to each other may be merged for efficiency. Thus two 4K reads may become one 8K read before it is ultimately handed to the disk, and so it will be counted (and queued) as only one I/O. This field lets you know how often this was done.”…””}”(hj$hžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1h·hŸh¶h K.hj!ubah}”(h]”h ]”h"]”h$]”h&]”uh1jðhjubeh}”(h]”h ]”h"]”h$]”h&]”uh1jÚhŸh¶h K1hj×hžhubjÛ)”}”(hŒeField 3 -- # of sectors read (unsigned long) This is the total number of sectors read successfully. ”h]”(já)”}”(hŒ-Field 3 -- # of sectors read (unsigned long)”h]”hŒ-Field 3 -- # of sectors read (unsigned long)”…””}”(hjBhžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1jàhŸh¶h K4hj>ubjñ)”}”(hhh]”h¸)”}”(hŒ6This is the total number of sectors read successfully.”h]”hŒ6This is the total number of sectors read successfully.”…””}”(hjShžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1h·hŸh¶h K4hjPubah}”(h]”h ]”h"]”h$]”h&]”uh1jðhj>ubeh}”(h]”h ]”h"]”h$]”h&]”uh1jÚhŸh¶h K4hj×hžhubjÛ)”}”(hŒ¼Field 4 -- # of milliseconds spent reading (unsigned int) This is the total number of milliseconds spent by all reads (as measured from blk_mq_alloc_request() to __blk_mq_end_request()). ”h]”(já)”}”(hŒ:Field 4 -- # of milliseconds spent reading (unsigned int)”h]”hŒ:Field 4 -- # of milliseconds spent reading (unsigned int)”…””}”(hjqhžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1jàhŸh¶h K8hjmubjñ)”}”(hhh]”h¸)”}”(hŒ€This is the total number of milliseconds spent by all reads (as measured from blk_mq_alloc_request() to __blk_mq_end_request()).”h]”hŒ€This is the total number of milliseconds spent by all reads (as measured from blk_mq_alloc_request() to __blk_mq_end_request()).”…””}”(hj‚hžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1h·hŸh¶h K7hjubah}”(h]”h ]”h"]”h$]”h&]”uh1jðhjmubeh}”(h]”h ]”h"]”h$]”h&]”uh1jÚhŸh¶h K8hj×hžhubjÛ)”}”(hŒmField 5 -- # of writes completed (unsigned long) This is the total number of writes completed successfully. ”h]”(já)”}”(hŒ1Field 5 -- # of writes completed (unsigned long)”h]”hŒ1Field 5 -- # of writes completed (unsigned long)”…””}”(hj hžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1jàhŸh¶h K;hjœubjñ)”}”(hhh]”h¸)”}”(hŒ:This is the total number of writes completed successfully.”h]”hŒ:This is the total number of writes completed successfully.”…””}”(hj±hžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1h·hŸh¶h K;hj®ubah}”(h]”h ]”h"]”h$]”h&]”uh1jðhjœubeh}”(h]”h ]”h"]”h$]”h&]”uh1jÚhŸh¶h K;hj×hžhubjÛ)”}”(hŒPField 6 -- # of writes merged (unsigned long) See the description of field 2. ”h]”(já)”}”(hŒ/Field 6 -- # of writes merged (unsigned long)”h]”hŒ/Field 6 -- # of writes merged (unsigned long)”…””}”(hjÏhžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1jàhŸh¶h K>hjËubjñ)”}”(hhh]”h¸)”}”(hŒSee the description of field 2.”h]”hŒSee the description of field 2.”…””}”(hjàhžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1h·hŸh¶h K>hjÝubah}”(h]”h ]”h"]”h$]”h&]”uh1jðhjËubeh}”(h]”h ]”h"]”h$]”h&]”uh1jÚhŸh¶h K>hj×hžhubjÛ)”}”(hŒkField 7 -- # of sectors written (unsigned long) This is the total number of sectors written successfully. ”h]”(já)”}”(hŒ0Field 7 -- # of sectors written (unsigned long)”h]”hŒ0Field 7 -- # of sectors written (unsigned long)”…””}”(hjþhžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1jàhŸh¶h KAhjúubjñ)”}”(hhh]”h¸)”}”(hŒ9This is the total number of sectors written successfully.”h]”hŒ9This is the total number of sectors written successfully.”…””}”(hjhžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1h·hŸh¶h KAhjubah}”(h]”h ]”h"]”h$]”h&]”uh1jðhjúubeh}”(h]”h ]”h"]”h$]”h&]”uh1jÚhŸh¶h KAhj×hžhubjÛ)”}”(hŒ½Field 8 -- # of milliseconds spent writing (unsigned int) This is the total number of milliseconds spent by all writes (as measured from blk_mq_alloc_request() to __blk_mq_end_request()). ”h]”(já)”}”(hŒ:Field 8 -- # of milliseconds spent writing (unsigned int)”h]”hŒ:Field 8 -- # of milliseconds spent writing (unsigned int)”…””}”(hj-hžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1jàhŸh¶h KEhj)ubjñ)”}”(hhh]”h¸)”}”(hŒThis is the total number of milliseconds spent by all writes (as measured from blk_mq_alloc_request() to __blk_mq_end_request()).”h]”hŒThis is the total number of milliseconds spent by all writes (as measured from blk_mq_alloc_request() to __blk_mq_end_request()).”…””}”(hj>hžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1h·hŸh¶h KDhj;ubah}”(h]”h ]”h"]”h$]”h&]”uh1jðhj)ubeh}”(h]”h ]”h"]”h$]”h&]”uh1jÚhŸh¶h KEhj×hžhubjÛ)”}”(hŒÈField 9 -- # of I/Os currently in progress (unsigned int) The only field that should go to zero. Incremented as requests are given to appropriate struct request_queue and decremented as they finish. ”h]”(já)”}”(hŒ:Field 9 -- # of I/Os currently in progress (unsigned int)”h]”hŒ:Field 9 -- # of I/Os currently in progress (unsigned int)”…””}”(hj\hžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1jàhŸh¶h KIhjXubjñ)”}”(hhh]”h¸)”}”(hŒŒThe only field that should go to zero. Incremented as requests are given to appropriate struct request_queue and decremented as they finish.”h]”hŒŒThe only field that should go to zero. Incremented as requests are given to appropriate struct request_queue and decremented as they finish.”…””}”(hjmhžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1h·hŸh¶h KHhjjubah}”(h]”h ]”h"]”h$]”h&]”uh1jðhjXubeh}”(h]”h ]”h"]”h$]”h&]”uh1jÚhŸh¶h KIhj×hžhubjÛ)”}”(hX9Field 10 -- # of milliseconds spent doing I/Os (unsigned int) This field increases so long as field 9 is nonzero. Since 5.0 this field counts jiffies when at least one request was started or completed. If request runs more than 2 jiffies then some I/O time might be not accounted in case of concurrent requests. ”h]”(já)”}”(hŒ=Field 10 -- # of milliseconds spent doing I/Os (unsigned int)”h]”hŒ=Field 10 -- # of milliseconds spent doing I/Os (unsigned int)”…””}”(hj‹hžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1jàhŸh¶h KPhj‡ubjñ)”}”(hhh]”(h¸)”}”(hŒ3This field increases so long as field 9 is nonzero.”h]”hŒ3This field increases so long as field 9 is nonzero.”…””}”(hjœhžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1h·hŸh¶h KLhj™ubh¸)”}”(hŒÅSince 5.0 this field counts jiffies when at least one request was started or completed. If request runs more than 2 jiffies then some I/O time might be not accounted in case of concurrent requests.”h]”hŒÅSince 5.0 this field counts jiffies when at least one request was started or completed. If request runs more than 2 jiffies then some I/O time might be not accounted in case of concurrent requests.”…””}”(hjªhžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1h·hŸh¶h KNhj™ubeh}”(h]”h ]”h"]”h$]”h&]”uh1jðhj‡ubeh}”(h]”h ]”h"]”h$]”h&]”uh1jÚhŸh¶h KPhj×hžhubjÛ)”}”(hXField 11 -- weighted # of milliseconds spent doing I/Os (unsigned int) This field is incremented at each I/O start, I/O completion, I/O merge, or read of these stats by the number of I/Os in progress (field 9) times the number of milliseconds spent doing I/O since the last update of this field. This can provide an easy measure of both I/O completion time and the backlog that may be accumulating. ”h]”(já)”}”(hŒFField 11 -- weighted # of milliseconds spent doing I/Os (unsigned int)”h]”hŒFField 11 -- weighted # of milliseconds spent doing I/Os (unsigned int)”…””}”(hjÈhžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1jàhŸh¶h KWhjÄubjñ)”}”(hhh]”h¸)”}”(hXHThis field is incremented at each I/O start, I/O completion, I/O merge, or read of these stats by the number of I/Os in progress (field 9) times the number of milliseconds spent doing I/O since the last update of this field. This can provide an easy measure of both I/O completion time and the backlog that may be accumulating.”h]”hXHThis field is incremented at each I/O start, I/O completion, I/O merge, or read of these stats by the number of I/Os in progress (field 9) times the number of milliseconds spent doing I/O since the last update of this field. This can provide an easy measure of both I/O completion time and the backlog that may be accumulating.”…””}”(hjÙhžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1h·hŸh¶h KShjÖubah}”(h]”h ]”h"]”h$]”h&]”uh1jðhjÄubeh}”(h]”h ]”h"]”h$]”h&]”uh1jÚhŸh¶h KWhj×hžhubjÛ)”}”(hŒqField 12 -- # of discards completed (unsigned long) This is the total number of discards completed successfully. ”h]”(já)”}”(hŒ3Field 12 -- # of discards completed (unsigned long)”h]”hŒ3Field 12 -- # of discards completed (unsigned long)”…””}”(hj÷hžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1jàhŸh¶h KZhjóubjñ)”}”(hhh]”h¸)”}”(hŒuŒ nametypes”}”(jI‰jr‰jA‰uh}”(jFh£jojKj>juuŒ footnote_refs”}”Œ citation_refs”}”Œ autofootnotes”]”Œautofootnote_refs”]”Œsymbol_footnotes”]”Œsymbol_footnote_refs”]”Œ footnotes”]”Œ citations”]”Œautofootnote_start”KŒsymbol_footnote_start”KŒ id_counter”Œcollections”ŒCounter”“”}”…”R”Œparse_messages”]”Œtransform_messages”]”Œtransformer”NŒinclude_log”]”Œ decoration”Nhžhub.