A backup strategy is more complex than creating a redundant copy of
disk storage and considering the strategy a success. A successful backup strategy must
detail how the backup media are rotated, how the media are archived, how the system will
be recovered, and what the backup software will do to create the backup. Although all
parts of the backup strategy are equally important, this tip will focus on the backup
script and will detail a flexible backup script that uses built-in Solaris software tools
which create a reliable local backup of a Solaris machine.
The backup script will accomplish the following
- Create a backup archive that is as easy to restore a single file
as it is to restore an entire file system.
- The backup script will run autonomously. The only human
intervention will be to swap media and review output.
- The filesystems or directories to backup can be specified in the
script. Using automounter you can even specify remote filesystems.
- The script will create a detailed log of the backup.
- The script will send an abbreviated email summary of the backup
to the administrator.
- After a successful backup, the script will verify to some extent
the contents of the backup media.
- The backup script will be able to run on any Solaris 2.6 or
greater machine without modification.
We use the well known utilities TAR, GZIP and
DD, because they are available on any Unix system. They are very well tested and
simple to use. In case of an emergency it is important to have a simple way to restore,
independent of complex tools and incompatible software releases.
The utility MT sends commands to a tape drive. Many of these commands are familiar, but some
are not. The script will use these mt commands.
- rewind – rewind the
- rewoffl – rewind the tape and
eject it (go offline)
- eom – space to end of recorded
media on tape
- weof – write count EOF marks
at current position on tape
- status – display current
status of tape
Click here for the Shell Script