Preparing a multi-volume dump on ECKD DASD

Red Hat Enterprise Linux 8.6 LPAR mode z/VM guest

Use zipl with the -M (--mvdump) command-line option or with the mvdump= configuration-file option to prepare a multi-volume dump on ECKD DASD.

zipl command line syntax for preparing devices for a multi-volume dump

To prepare a set of DASD devices for a multi-volume dump, you must specify:

-M <dump_device_list>: specifies a file that contains the device nodes of the dump partitions, separated by one or more line feed characters (0x0a). zipl writes a dump signature to each involved partition and installs the stand-alone multi-volume dump tool on each involved volume. Duplicate partitions are not allowed. A maximum of 32 partitions can be listed. The volumes must be formatted with cdl and use block size 4096.

Optionally, you can also specify:

-f or --force: to force that no signature checking takes place when dumping. Any data on all involved partitions is overwritten without warning.
-n: to suppress confirmation prompts to allow unattended processing (for example, from a script). This option is available on the command line only.
<size>: for the amount of memory to be dumped. The value is a decimal number that can optionally be suffixed with K for kilobytes, M for megabytes, or G for gigabytes. The value is rounded to the next megabyte boundary.
If you limit the dump size below the amount of memory that is used by the system to be dumped, the resulting dump is incomplete.

DASD or tape dump devices are not formatted with a file system so no target directory can be specified. See Using the Dump Tools on Red Hat® Enterprise Linux® 8.6, SC34-7718 for details about processing these dumps.

Figure 1 summarizes how you can specify a multi-volume DASD dump configuration in a configuration file.

Figure 1. zipl syntax for preparing DASD devices for a multi-volume dump - configuration file mode

[<section_name>]
mvdump=<dump_device_list>,<size>

Example

The following command prepares two DASD partitions /dev/dasdc1, /dev/dasdd1 for a multi-volume dump and suppresses confirmation prompts that require an operator response:

# zipl -M mvdump.conf -n

where the mvdump.conf file contains the two partitions that are separated by line breaks:

/dev/dasdc1
/dev/dasdd1

An equivalent section in a configuration file might look like this example:

[multi_volume_dump]
mvdump=mvdump.conf

There is no configuration file equivalent for option -n. To use this option for a multi-volume DASD dump configuration in a configuration file, it must be specified with the zipl command that processes the configuration.

If the configuration file is called /etc/myxmp.conf:

# zipl -c /etc/myxmp.conf multi_volume_dump -n