Next: , Previous: Magnetic Tape Control, Up: Backup Parameters

5.4.3 User Hooks

User hooks are shell functions executed before and after each tar invocation. Thus, there are backup hooks, which are executed before and after dumping each file system, and restore hooks, executed before and after restoring a file system. Each user hook is a shell function taking four arguments:

— User Hook Function: hook level host fs fsname

Its arguments are:

level
Current backup or restore level.
host
Name or IP address of the host machine being dumped or restored.
fs
Full path name to the file system being dumped or restored.
fsname
File system name with directory separators replaced with colons. This is useful, e.g., for creating unique files.

Following variables keep the names of user hook functions

— Backup variable: DUMP_BEGIN

Dump begin function. It is executed before dumping the file system.

— Backup variable: DUMP_END

Executed after dumping the file system.

— Backup variable: RESTORE_BEGIN

Executed before restoring the file system.

— Backup variable: RESTORE_END

Executed after restoring the file system.