€•Y(Œsphinx.addnodes”Œdocument”“”)”}”(Œ rawsource”Œ”Œchildren”]”(Œ translations”Œ LanguagesNode”“”)”}”(hhh]”(hŒ pending_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/arch/s390/zfcpdump”Œmodname”NŒ classname”NŒ refexplicit”ˆuŒtagname”hhh ubh)”}”(hhh]”hŒChinese (Traditional)”…””}”hh2sbah}”(h]”h ]”h"]”h$]”h&]”Œ refdomain”h)Œreftype”h+Œ reftarget”Œ&/translations/zh_TW/arch/s390/zfcpdump”Œmodname”NŒ classname”NŒ refexplicit”ˆuh1hhh ubh)”}”(hhh]”hŒItalian”…””}”hhFsbah}”(h]”h ]”h"]”h$]”h&]”Œ refdomain”h)Œreftype”h+Œ reftarget”Œ&/translations/it_IT/arch/s390/zfcpdump”Œmodname”NŒ classname”NŒ refexplicit”ˆuh1hhh ubh)”}”(hhh]”hŒJapanese”…””}”hhZsbah}”(h]”h ]”h"]”h$]”h&]”Œ refdomain”h)Œreftype”h+Œ reftarget”Œ&/translations/ja_JP/arch/s390/zfcpdump”Œmodname”NŒ classname”NŒ refexplicit”ˆuh1hhh ubh)”}”(hhh]”hŒKorean”…””}”hhnsbah}”(h]”h ]”h"]”h$]”h&]”Œ refdomain”h)Œreftype”h+Œ reftarget”Œ&/translations/ko_KR/arch/s390/zfcpdump”Œmodname”NŒ classname”NŒ refexplicit”ˆuh1hhh ubh)”}”(hhh]”hŒSpanish”…””}”hh‚sbah}”(h]”h ]”h"]”h$]”h&]”Œ refdomain”h)Œreftype”h+Œ reftarget”Œ&/translations/sp_SP/arch/s390/zfcpdump”Œmodname”NŒ classname”NŒ refexplicit”ˆuh1hhh ubeh}”(h]”h ]”h"]”h$]”h&]”Œcurrent_language”ŒEnglish”uh1h hhŒ _document”hŒsource”NŒline”NubhŒsection”“”)”}”(hhh]”(hŒtitle”“”)”}”(hŒ"The s390 SCSI dump tool (zfcpdump)”h]”hŒ"The s390 SCSI dump tool (zfcpdump)”…””}”(hh¨hžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1h¦hh£hžhhŸŒ@/var/lib/git/docbuild/linux/Documentation/arch/s390/zfcpdump.rst”h KubhŒ paragraph”“”)”}”(hXSystem z machines (z900 or higher) provide hardware support for creating system dumps on SCSI disks. The dump process is initiated by booting a dump tool, which has to create a dump of the current (probably crashed) Linux image. In order to not overwrite memory of the crashed Linux with data of the dump tool, the hardware saves some memory plus the register sets of the boot CPU before the dump tool is loaded. There exists an SCLP hardware interface to obtain the saved memory afterwards. Currently 32 MB are saved.”h]”hXSystem z machines (z900 or higher) provide hardware support for creating system dumps on SCSI disks. The dump process is initiated by booting a dump tool, which has to create a dump of the current (probably crashed) Linux image. In order to not overwrite memory of the crashed Linux with data of the dump tool, the hardware saves some memory plus the register sets of the boot CPU before the dump tool is loaded. There exists an SCLP hardware interface to obtain the saved memory afterwards. Currently 32 MB are saved.”…””}”(hh¹hžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1h·hŸh¶h Khh£hžhubh¸)”}”(hXThis zfcpdump implementation consists of a Linux dump kernel together with a user space dump tool, which are loaded together into the saved memory region below 32 MB. zfcpdump is installed on a SCSI disk using zipl (as contained in the s390-tools package) to make the device bootable. The operator of a Linux system can then trigger a SCSI dump by booting the SCSI disk, where zfcpdump resides on.”h]”hXThis zfcpdump implementation consists of a Linux dump kernel together with a user space dump tool, which are loaded together into the saved memory region below 32 MB. zfcpdump is installed on a SCSI disk using zipl (as contained in the s390-tools package) to make the device bootable. The operator of a Linux system can then trigger a SCSI dump by booting the SCSI disk, where zfcpdump resides on.”…””}”(hhÇhžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1h·hŸh¶h K hh£hžhubh¸)”}”(hXÄThe user space dump tool accesses the memory of the crashed system by means of the /proc/vmcore interface. This interface exports the crashed system's memory and registers in ELF core dump format. To access the memory which has been saved by the hardware SCLP requests will be created at the time the data is needed by /proc/vmcore. The tail part of the crashed systems memory which has not been stashed by hardware can just be copied from real memory.”h]”hXÆThe user space dump tool accesses the memory of the crashed system by means of the /proc/vmcore interface. This interface exports the crashed system’s memory and registers in ELF core dump format. To access the memory which has been saved by the hardware SCLP requests will be created at the time the data is needed by /proc/vmcore. The tail part of the crashed systems memory which has not been stashed by hardware can just be copied from real memory.”…””}”(hhÕhžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1h·hŸh¶h Khh£hžhubh¸)”}”(hŒXTo build a dump enabled kernel the kernel config option CONFIG_CRASH_DUMP has to be set.”h]”hŒXTo build a dump enabled kernel the kernel config option CONFIG_CRASH_DUMP has to be set.”…””}”(hhãhžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1h·hŸh¶h Khh£hžhubh¸)”}”(hŒKTo get a valid zfcpdump kernel configuration use "make zfcpdump_defconfig".”h]”hŒOTo get a valid zfcpdump kernel configuration use “make zfcpdump_defconfigâ€.”…””}”(hhñhžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1h·hŸh¶h Khh£hžhubh¸)”}”(hŒmThe s390 zipl tool looks for the zfcpdump kernel and optional initrd/initramfs under the following locations:”h]”hŒmThe s390 zipl tool looks for the zfcpdump kernel and optional initrd/initramfs under the following locations:”…””}”(hhÿhžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1h·hŸh¶h K hh£hžhubhŒ bullet_list”“”)”}”(hhh]”(hŒ list_item”“”)”}”(hŒ,kernel: /zfcpdump.image”h]”h¸)”}”(hjh]”hŒ,kernel: /zfcpdump.image”…””}”(hjhžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1h·hŸh¶h K#hjubah}”(h]”h ]”h"]”h$]”h&]”uh1jhjhžhhŸh¶h Nubj)”}”(hŒ*ramdisk: /zfcpdump.rd ”h]”h¸)”}”(hŒ)ramdisk: /zfcpdump.rd”h]”hŒ)ramdisk: /zfcpdump.rd”…””}”(hj/hžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1h·hŸh¶h K$hj+ubah}”(h]”h ]”h"]”h$]”h&]”uh1jhjhžhhŸh¶h Nubeh}”(h]”h ]”h"]”h$]”h&]”Œbullet”Œ*”uh1j hŸh¶h K#hh£hžhubh¸)”}”(hŒ