diff options
author | Michael Holzheu <holzheu@linux.vnet.ibm.com> | 2014-04-14 05:56:07 -0400 |
---|---|---|
committer | Martin Schwidefsky <schwidefsky@de.ibm.com> | 2014-05-20 02:58:44 -0400 |
commit | 7d4c738ce522692cc328869a6633704e535d7124 (patch) | |
tree | 6c38f3fbc3e62f06b00cd5bf8e1718ff171e6ee4 /Documentation/s390 | |
parent | bf28a5970de3a349ec05cea45ca5272404b6609f (diff) |
s390/zfcpdump: Update documentation in zfcpdump.txt
Do the following changes:
- Document new /proc/vmcore interface
- Document partition dump external initramfs with s390-tools-1.24.0
- Remove initramfs config file because initramfs is now built automatically
in s390-tools
- Replace description of kernel config options with "make zfcpdump_defconfig"
- Some editorial changes
Signed-off-by: Michael Holzheu <holzheu@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Diffstat (limited to 'Documentation/s390')
-rw-r--r-- | Documentation/s390/zfcpdump.txt | 71 |
1 files changed, 18 insertions, 53 deletions
diff --git a/Documentation/s390/zfcpdump.txt b/Documentation/s390/zfcpdump.txt index 1cae248c3b77..dc929be96016 100644 --- a/Documentation/s390/zfcpdump.txt +++ b/Documentation/s390/zfcpdump.txt | |||
@@ -1,15 +1,15 @@ | |||
1 | s390 SCSI dump tool (zfcpdump) | 1 | The s390 SCSI dump tool (zfcpdump) |
2 | 2 | ||
3 | System z machines (z900 or higher) provide hardware support for creating system | 3 | System z machines (z900 or higher) provide hardware support for creating system |
4 | dumps on SCSI disks. The dump process is initiated by booting a dump tool, which | 4 | dumps on SCSI disks. The dump process is initiated by booting a dump tool, which |
5 | has to create a dump of the current (probably crashed) Linux image. In order to | 5 | has to create a dump of the current (probably crashed) Linux image. In order to |
6 | not overwrite memory of the crashed Linux with data of the dump tool, the | 6 | not overwrite memory of the crashed Linux with data of the dump tool, the |
7 | hardware saves some memory plus the register sets of the boot cpu before the | 7 | hardware saves some memory plus the register sets of the boot CPU before the |
8 | dump tool is loaded. There exists an SCLP hardware interface to obtain the saved | 8 | dump tool is loaded. There exists an SCLP hardware interface to obtain the saved |
9 | memory afterwards. Currently 32 MB are saved. | 9 | memory afterwards. Currently 32 MB are saved. |
10 | 10 | ||
11 | This zfcpdump implementation consists of a Linux dump kernel together with | 11 | This zfcpdump implementation consists of a Linux dump kernel together with |
12 | a userspace dump tool, which are loaded together into the saved memory region | 12 | a user space dump tool, which are loaded together into the saved memory region |
13 | below 32 MB. zfcpdump is installed on a SCSI disk using zipl (as contained in | 13 | below 32 MB. zfcpdump is installed on a SCSI disk using zipl (as contained in |
14 | the s390-tools package) to make the device bootable. The operator of a Linux | 14 | the s390-tools package) to make the device bootable. The operator of a Linux |
15 | system can then trigger a SCSI dump by booting the SCSI disk, where zfcpdump | 15 | system can then trigger a SCSI dump by booting the SCSI disk, where zfcpdump |
@@ -19,68 +19,33 @@ The kernel part of zfcpdump is implemented as a debugfs file under "zcore/mem", | |||
19 | which exports memory and registers of the crashed Linux in an s390 | 19 | which exports memory and registers of the crashed Linux in an s390 |
20 | standalone dump format. It can be used in the same way as e.g. /dev/mem. The | 20 | standalone dump format. It can be used in the same way as e.g. /dev/mem. The |
21 | dump format defines a 4K header followed by plain uncompressed memory. The | 21 | dump format defines a 4K header followed by plain uncompressed memory. The |
22 | register sets are stored in the prefix pages of the respective cpus. To build a | 22 | register sets are stored in the prefix pages of the respective CPUs. To build a |
23 | dump enabled kernel with the zcore driver, the kernel config option | 23 | dump enabled kernel with the zcore driver, the kernel config option |
24 | CONFIG_CRASH_DUMP has to be set. When reading from "zcore/mem", the part of | 24 | CONFIG_CRASH_DUMP has to be set. When reading from "zcore/mem", the part of |
25 | memory, which has been saved by hardware is read by the driver via the SCLP | 25 | memory, which has been saved by hardware is read by the driver via the SCLP |
26 | hardware interface. The second part is just copied from the non overwritten real | 26 | hardware interface. The second part is just copied from the non overwritten real |
27 | memory. | 27 | memory. |
28 | 28 | ||
29 | The userspace application of zfcpdump can reside e.g. in an intitramfs or an | 29 | Since kernel version 3.12 also the /proc/vmcore file can also be used to access |
30 | initrd. It reads from zcore/mem and writes the system dump to a file on a | 30 | the dump. |
31 | SCSI disk. | ||
32 | 31 | ||
33 | To build a zfcpdump kernel use the following settings in your kernel | 32 | To get a valid zfcpdump kernel configuration use "make zfcpdump_defconfig". |
34 | configuration: | ||
35 | * CONFIG_CRASH_DUMP=y | ||
36 | * Enable ZFCP driver | ||
37 | * Enable SCSI driver | ||
38 | * Enable ext2 and ext3 filesystems | ||
39 | * Disable as many features as possible to keep the kernel small. | ||
40 | E.g. network support is not needed at all. | ||
41 | 33 | ||
42 | To use the zfcpdump userspace application in an initramfs you have to do the | 34 | The s390 zipl tool looks for the zfcpdump kernel and optional initrd/initramfs |
43 | following: | 35 | under the following locations: |
44 | 36 | ||
45 | * Copy the zfcpdump executable somewhere into your Linux tree. | 37 | * kernel: <zfcpdump directory>/zfcpdump.image |
46 | E.g. to "arch/s390/boot/zfcpdump. If you do not want to include | 38 | * ramdisk: <zfcpdump directory>/zfcpdump.rd |
47 | shared libraries, compile the tool with the "-static" gcc option. | ||
48 | * If you want to include e2fsck, add it to your source tree, too. The zfcpdump | ||
49 | application attempts to start /sbin/e2fsck from the ramdisk. | ||
50 | * Use an initramfs config file like the following: | ||
51 | 39 | ||
52 | dir /dev 755 0 0 | 40 | The zfcpdump directory is defined in the s390-tools package. |
53 | nod /dev/console 644 0 0 c 5 1 | ||
54 | nod /dev/null 644 0 0 c 1 3 | ||
55 | nod /dev/sda1 644 0 0 b 8 1 | ||
56 | nod /dev/sda2 644 0 0 b 8 2 | ||
57 | nod /dev/sda3 644 0 0 b 8 3 | ||
58 | nod /dev/sda4 644 0 0 b 8 4 | ||
59 | nod /dev/sda5 644 0 0 b 8 5 | ||
60 | nod /dev/sda6 644 0 0 b 8 6 | ||
61 | nod /dev/sda7 644 0 0 b 8 7 | ||
62 | nod /dev/sda8 644 0 0 b 8 8 | ||
63 | nod /dev/sda9 644 0 0 b 8 9 | ||
64 | nod /dev/sda10 644 0 0 b 8 10 | ||
65 | nod /dev/sda11 644 0 0 b 8 11 | ||
66 | nod /dev/sda12 644 0 0 b 8 12 | ||
67 | nod /dev/sda13 644 0 0 b 8 13 | ||
68 | nod /dev/sda14 644 0 0 b 8 14 | ||
69 | nod /dev/sda15 644 0 0 b 8 15 | ||
70 | file /init arch/s390/boot/zfcpdump 755 0 0 | ||
71 | file /sbin/e2fsck arch/s390/boot/e2fsck 755 0 0 | ||
72 | dir /proc 755 0 0 | ||
73 | dir /sys 755 0 0 | ||
74 | dir /mnt 755 0 0 | ||
75 | dir /sbin 755 0 0 | ||
76 | 41 | ||
77 | * Issue "make image" to build the zfcpdump image with initramfs. | 42 | The user space application of zfcpdump can reside in an intitramfs or an |
43 | initrd. It can also be included in a built-in kernel initramfs. The application | ||
44 | reads from /proc/vmcore or zcore/mem and writes the system dump to a SCSI disk. | ||
78 | 45 | ||
79 | In a Linux distribution the zfcpdump enabled kernel image must be copied to | 46 | The s390-tools package version 1.24.0 and above builds an external zfcpdump |
80 | /usr/share/zfcpdump/zfcpdump.image, where the s390 zipl tool is looking for the | 47 | initramfs with a user space application that writes the dump to a SCSI |
81 | dump kernel when preparing a SCSI dump disk. | 48 | partition. |
82 | |||
83 | If you use a ramdisk copy it to "/usr/share/zfcpdump/zfcpdump.rd". | ||
84 | 49 | ||
85 | For more information on how to use zfcpdump refer to the s390 'Using the Dump | 50 | For more information on how to use zfcpdump refer to the s390 'Using the Dump |
86 | Tools book', which is available from | 51 | Tools book', which is available from |