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Diffstat (limited to 'Documentation/s390/zfcpdump.txt')
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diff --git a/Documentation/s390/zfcpdump.txt b/Documentation/s390/zfcpdump.txt deleted file mode 100644 index cf45d27c460..00000000000 --- a/Documentation/s390/zfcpdump.txt +++ /dev/null @@ -1,87 +0,0 @@ -s390 SCSI dump tool (zfcpdump) - -System 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. - -This zfcpdump implementation consists of a Linux dump kernel together with -a userspace 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. - -The kernel part of zfcpdump is implemented as a debugfs file under "zcore/mem", -which exports memory and registers of the crashed Linux in an s390 -standalone dump format. It can be used in the same way as e.g. /dev/mem. The -dump format defines a 4K header followed by plain uncompressed memory. The -register sets are stored in the prefix pages of the respective cpus. To build a -dump enabled kernel with the zcore driver, the kernel config option -CONFIG_ZFCPDUMP has to be set. When reading from "zcore/mem", the part of -memory, which has been saved by hardware is read by the driver via the SCLP -hardware interface. The second part is just copied from the non overwritten real -memory. - -The userspace application of zfcpdump can reside e.g. in an intitramfs or an -initrd. It reads from zcore/mem and writes the system dump to a file on a -SCSI disk. - -To build a zfcpdump kernel use the following settings in your kernel -configuration: - * CONFIG_ZFCPDUMP=y - * Enable ZFCP driver - * Enable SCSI driver - * Enable ext2 and ext3 filesystems - * Disable as many features as possible to keep the kernel small. - E.g. network support is not needed at all. - -To use the zfcpdump userspace application in an initramfs you have to do the -following: - - * Copy the zfcpdump executable somewhere into your Linux tree. - E.g. to "arch/s390/boot/zfcpdump. If you do not want to include - shared libraries, compile the tool with the "-static" gcc option. - * If you want to include e2fsck, add it to your source tree, too. The zfcpdump - application attempts to start /sbin/e2fsck from the ramdisk. - * Use an initramfs config file like the following: - - dir /dev 755 0 0 - nod /dev/console 644 0 0 c 5 1 - nod /dev/null 644 0 0 c 1 3 - nod /dev/sda1 644 0 0 b 8 1 - nod /dev/sda2 644 0 0 b 8 2 - nod /dev/sda3 644 0 0 b 8 3 - nod /dev/sda4 644 0 0 b 8 4 - nod /dev/sda5 644 0 0 b 8 5 - nod /dev/sda6 644 0 0 b 8 6 - nod /dev/sda7 644 0 0 b 8 7 - nod /dev/sda8 644 0 0 b 8 8 - nod /dev/sda9 644 0 0 b 8 9 - nod /dev/sda10 644 0 0 b 8 10 - nod /dev/sda11 644 0 0 b 8 11 - nod /dev/sda12 644 0 0 b 8 12 - nod /dev/sda13 644 0 0 b 8 13 - nod /dev/sda14 644 0 0 b 8 14 - nod /dev/sda15 644 0 0 b 8 15 - file /init arch/s390/boot/zfcpdump 755 0 0 - file /sbin/e2fsck arch/s390/boot/e2fsck 755 0 0 - dir /proc 755 0 0 - dir /sys 755 0 0 - dir /mnt 755 0 0 - dir /sbin 755 0 0 - - * Issue "make image" to build the zfcpdump image with initramfs. - -In a Linux distribution the zfcpdump enabled kernel image must be copied to -/usr/share/zfcpdump/zfcpdump.image, where the s390 zipl tool is looking for the -dump kernel when preparing a SCSI dump disk. - -If you use a ramdisk copy it to "/usr/share/zfcpdump/zfcpdump.rd". - -For more information on how to use zfcpdump refer to the s390 'Using the Dump -Tools book', which is available from -http://www.ibm.com/developerworks/linux/linux390. |