Appendix C Re-Installation Of Red Hat Linux And Preserving Existing Data; Preservation Of Existing Data On An Iseries Red Hat Linux Logical; Partition; Additional Considerations: Iseries Virtual Disks - Red Hat LINUX 7.1 - ISERIES Manual

Section C.2:Additional Considerations: iSeries Virtual Disks
C Re-installation of Red Hat Linux and
Preserving Existing Data
C.1 Preservation of Existing Data on an iSeries Red
Hat Linux Logical Partition
Generally speaking, installing Red Hat Linux over a prior installation (including Red Hat Linux) will
destroy some and often all the data on the disks (virtual and physical) attatched to that Logical Partition
(LPAR). If these disks contain data which is important to you, the data should be protected. There are
a variety of ways to do this, some of which are unique to the iSeries environment.
1. The data can be saved and removed from the system before the (re)installation. This would be the
ordinary and traditional Linux means of preserving data (tarballs, etc.).
2. Moving or copying the data (via FTP, NFS, etc.) to another Logical Partition, either OS/400 or
Linux. Since each iSeries Logical Partition is independent, one Logical Partition's data is unaf-
fected by a reinstall in a different Logical Partition.
3. Removing the disks from the Logical Partition during the installation. If your Red Hat Linux instal-
lation contains more than one disk (virtual or physical) and that disk does not contain data from the
Red Hat installation (e.g. is mounted at /home/myuserid, mounted as the directories contain-
ing the data base data) it can be removed from the Logical Partition for the duration of the reinstall,
and then added back in after the installation is complete. See the Configuring Linux in a Guest Par-
tition document ( http://publib.boulder.ibm.com/pubs/html/as400/v5r1/ic2924/info/rzalm/rzalm-
linuxkickoff.htm) for details on how these functions are performed.
4. Adding disks, copying the data, and then removing the new disks during the installation. If you
have data to spare on an OS/400 partition, creating a new virtual disk, mounting it, copying the
data, and then removing it during the installation is another way of obtaining the benefits of step
3, even if you did not initially plan for it. After the installation, the disk can be added back and
permanently mounted, or simply copied back and the new disk deleted. A similar procedure could
be used for a spare physical disk.

C.2 Additional Considerations: iSeries Virtual Disks

When planning a new installation, the flexibility of virtual disks enable strategies not commonplace
in today's world of large physical disks. If you plan on using virtual disks, having one large enough
to hold the Red Hat Linux distribution and another holding applications and application data is one
strategy worth considering. Another strategy might be a single partition on a virtual disk holding a
particular application.
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