Examples: Directives to Back Up Specific Directories on a UNIX Client

Assume you want to save only the directory /aaa/zzz on client 123 and no others. This directive restricts Backup from walking the directories /aaa and /zzz to locate and back up other files or subdirectories. This directive invokes a UNIX application-specific module (uasm) called null. The use of null skips files in the directory specified; the use of +null skips files in the directory specified as well as those below the directory specified. The content of the directive to back up only /aaa/zzz appears as follows:

<< / >>  uasm: 	aaa  null: *.?<< /aaa >>	  uasm: zzz<< /aaa/zzz >>   +uasm: *.?*

In another example, assume you want to back up all non-root mounted disks, and back up the /home and /users directories off the root disk. You also want to back up the cron files and the calendar databases. For each client, the Save Set attribute contains the value All. The directive appears as follows:

<< / >>  uasm: home users var  null: *.?*  +null: core<< /home >>  +compression: *.?*  +null: core<< /users >> *   compression  +null: core<< /var >>  uasm: spool  null: *.?*  +null: core<< /var/spool >>  uasm: calendar cron  null: *.?*  +null: core<< /var/spool/calendar >>  +compression: *.?*  +null: core<< /var/spool/cron >>  +compression: *.?*  +null: core<< /cdrom >>  null: *.?*<< /opt >>  null: *.?*<< /tmp >>  null: *.?*<< /usr >>  null: *.?*

The use of null as part of a directive instructs Backup not to save the specified files during the particular backup, but to include an entry in the index listing created by Backup to indicate that the files were included in the backup operation. Because the files are included in the index, the filenames are available for browsing in the directory and the view of the filesystem through Backup corresponds to the actual filesystem. That is, the recover program's GUI displays files that are available for recovery, even if you skipped the files in more recent backups and the data available for recovery is not as recent as the data available for other files.

This behavior differs slightly from the behavior of the skip uasm directive. The skip uasm results in a view of your filesystem from the browser that reflects the backed-up data, not the closest approximation to the actual filesystem. For these reasons as well as other, more technical, advantages, the use of null is recommended over skip.