zfcpdump: S390 SCSI dump tool (Version 3)
=========================================
zfcpdump is used for creating System dumps for Linux on System z. It has two
parts: a zfcpdump enabled Linux kernel and a user space application.

This is the 3rd version of zfcpdump which uses the upstream kernel
version 3.12 or above. This version writes the dump to a partition in
contrast to the previous versions where the dump was written to
a file system.

The user space application of zfcpdump can reside either in an intitramfs or an
initrd. It reads from /proc/vmcore, provided by the kernel part, and writes the
system dump to a SCSI disk partition.

To build a zfcpdump enabled kernel use the following settings in your kernel
configuration:

 * CONFIG_ZFCPDUMP=y
 * CONFIG_BLK_DEV_INITRD=y
 * CONFIG_EFI_PARTITION=y for using GPT disk layout
 * CONFIG_MSDOS_PARTITION=y for using MSDOS disk layout
 * BLK_DEV_SD=y
 * Enable ZFCP driver
 * Enable SCSI driver
 * Disable as many features as possible to keep the kernel small.
   E.g. network and file system support is not needed at all.

You can use "make zfcpdump_defconfig" as a starting point for your kernel
configuration.

 * Issue "make bzImage" to build the zfcpdump kernel image.

In a Linux distribution the zfcpdump enabled kernel image must be copied to
/lib/s390-tools/zfcpdump/zfcpdump-image, where the s390 zipl tool is
looking for the dump kernel when preparing a SCSI dump disk.

Create and install initrd
=========================

 * make

Builds "cpioinit" and statically linked "zfcpdump" application. Then cpioinit
is used to integrate the zfcpdump application into the cpio archive
zfcpdump_part.rd.

 * make install

The initrd zfcpdump_part.rd is installed to "/lib/s390-tools/zfcpdump/".

Additional information
======================
For more information on how to use zfcpdump and zipl refer to the s390
'Using the Dump Tools' book, which is available from:
http://www.ibm.com/developerworks/linux/linux390.
