Archiving And Backing Up Critical Data; Overview Of Archiving Z/Vm System Data - IBM ZVM - FOR LINUX V6 RELEASE 1 Getting Started

Archiving and backing up critical data

Archiving stores large bodies of data (for example, an entire disk image) for
safekeeping, and should be a part of your disaster recovery plan. The data should
be mutually consistent, so you can be running, but cannot be making changes. Do
archiving on regular intervals, such as weekly or monthly, or whenever you do
major software changes. These archives allow you to restore entire systems quickly.
In contrast to archiving, backups store incremental changes, such as changes to
individual files, and you can do backups during system operations. Backups are
part of an on-demand file-level recovery system and you should do backups daily.
To restore backups, you need a running system, so after a system disaster, use your
archive to restore the entire system, then use your backups to restore files.
Sometimes the terms "archive" and "backup" are used to mean the same thing.
This topic uses the term "archive" and describes how to archive large bodies of
data such as disks. For backups on z/VM, use an incremental backup system, such
as Tivoli
documentation for your backup product.
On z/VM, archive:
v The z/VM system disks
v The z/VM spooling system, especially named save segments (NSSs) and
v Each major Linux kernel or installed software change.
It is not necessary to archive the z/VM paging space, since these disks hold data
valid only for the currently-running z/VM system.
z/VM provides two service programs for archiving:
v The DASD Dump Restore (DDR) utility program allows you to create archives of
v SPXTAPE produces an archive of spool files. Since NSSs (like CMS) and DCSSs
Related information:
v "DDR" in z/VM: CP Commands and Utilities Reference, SC24-6175
v "SPXTAPE" in z/VM: CP Commands and Utilities Reference, SC24-6175

Overview of archiving z/VM system data

At installation time, you should have archived the z/VM 610RES, 610W01, and
610W02 system disks. During the procedure, you created a tape that has the
DDRXA program and a copy of all the system disks. DDRXA is a standalone utility
program that you can load (IPL) from the tape, then use to restore the system to
disk. Because DDRXA does not require an operating system, the archive tape is
useful for disasters and disaster tests in which z/VM must be restored.
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z/VM: Getting Started with Linux on System z
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Storage Manager. For incremental backup procedures, consult the
discontiguous saved segments (DCSSs)
minidisks and complete DASD volumes. The program does not do incremental
backups, so all data on a disk is archived whether or not it has changed. There
are two versions of the program: one is the DDR command, which you can issue
from CMS; the other is a standalone program that you can load (IPL).
are part of the spooling system, you should archive the spooling system. If
problems develop with the spooling system and you need to do a CLEAN start
of z/VM, it is much easier to restore archived NSSs and DCSSs instead of
rebuilding them.