1 ==================================
2 The s390 SCSI dump tool (zfcpdump)
3 ==================================
4
5 System z machines (z900 or higher) provide har
6 dumps on SCSI disks. The dump process is initi
7 has to create a dump of the current (probably
8 not overwrite memory of the crashed Linux with
9 hardware saves some memory plus the register s
10 dump tool is loaded. There exists an SCLP hard
11 memory afterwards. Currently 32 MB are saved.
12
13 This zfcpdump implementation consists of a Lin
14 a user space dump tool, which are loaded toget
15 below 32 MB. zfcpdump is installed on a SCSI d
16 the s390-tools package) to make the device boo
17 system can then trigger a SCSI dump by booting
18 resides on.
19
20 The user space dump tool accesses the memory o
21 of the /proc/vmcore interface. This interface
22 memory and registers in ELF core dump format.
23 been saved by the hardware SCLP requests will
24 is needed by /proc/vmcore. The tail part of th
25 has not been stashed by hardware can just be c
26
27 To build a dump enabled kernel the kernel conf
28 has to be set.
29
30 To get a valid zfcpdump kernel configuration u
31
32 The s390 zipl tool looks for the zfcpdump kern
33 under the following locations:
34
35 * kernel: <zfcpdump directory>/zfcpdump.image
36 * ramdisk: <zfcpdump directory>/zfcpdump.rd
37
38 The zfcpdump directory is defined in the s390-
39
40 The user space application of zfcpdump can res
41 initrd. It can also be included in a built-in
42 reads from /proc/vmcore or zcore/mem and write
43
44 The s390-tools package version 1.24.0 and abov
45 initramfs with a user space application that w
46 partition.
47
48 For more information on how to use zfcpdump re
49 Tools' book, which is available from IBM Knowl
50 https://www.ibm.com/support/knowledgecenter/li
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