Backup options for virtual and directly attached disk

 

Read to learn about backup options for virtual and directly attached disks for Linux and i5/OS^® utilities.

There are two types of options for backing up and recovering data involving Linux partitions on the iSeries™ server:

• Utilities that run within Linux

• Commands that run within i5/OS

 

Utilities that run within Linux

Utilities that run within Linux benefit those users who have Linux installed to a native disk and those users who cannot vary off their Linux partition while they are backing up data. The most common data backup utility in Linux is the tar (a contraction of tape archive) utility. The tar utility archives files and directories into one file that you can save in either of two ways:

• You can write the file directly to a virtual or directly attached tape device. For information about this alternative, see Save and restore hosted Linux files to and from the host's shared tape drive.

• You can write the file to a file in the partition's file system. Following is an example of this alternative.

Example: tar -cvf /tmp/etc.tar /etc

Where, in the above example:

Variable	Description
c	create a tar file
v	verbose (show the files that are being added to the tar file
f	name of the tar file follows
/tmp/etc.tar	name of the tar file
/etc	object to be added to the tar file

Since /etc is a directory, the utility adds all the contents of the directory and its subdirectories to the tar file.

After you create the tar, you can save it to an offline medium in several ways, including writing it to a virtual or directly attached tape device or copying it to the IFS for inclusion in a subsequent save/restore operation.

You can tar the data on a Linux partition during normal server usage, and you can easily automate and start the tar utility by using the partition's cron daemon (a scheduling mechanism for Linux; cron is an abbreviation of chronology). You can also use the at utility to schedule a single backup request. For example, if you want to use the tar utility to back up the /etc directory at 10 p.m. on the 19th of September, you could enter the following Linux command:

at 10pm Sep 19 -f tar.command

For additional information about the tar, at, and cron utilities, use the Linux man (an abbreviation for manual) command. For example, man tar

 

i5/OS commands

Users of virtual disks also have powerful tools to use in i5/OS for backup and recovery. They can use the Save Object (SAV) and Restore Object (RST) commands to save and restore entire virtual disks in their current state.

The SAV command saves the directory that has the same name as the virtual disk under the QFPNWSSTG directory in the integrated file system. This method of backup and recovery is most effective if the Linux kernel is saved in a PrEP start partition on the virtual disk. On most Linux distributions, this normally occurs as part of a default installation.

If you save the Linux kernel in a PrEP partition, you can restore and start the Linux partition after a total iSeries reinstallation. You can also transport and restore saved virtual disks to other iSeries servers via FTP and tape.

 

Parent topic:

Back up and recover a logical partition