tar: Scripted Backups

1 
1 5.5 Using the Backup Scripts
1 ============================
1 
1 The syntax for running a backup script is:
1 
1      backup --level=LEVEL --time=TIME
1 
1    The '--level' option requests the dump level.  Thus, to produce a
1 full dump, specify '--level=0' (this is the default, so '--level' may be
1 omitted if its value is '0')(1).
1 
1    The '--time' option determines when should the backup be run.  TIME
1 may take three forms:
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1 HH:MM
1 
1      The dump must be run at HH hours MM minutes.
1 
1 HH
1 
1      The dump must be run at HH hours.
1 
1 now
1 
1      The dump must be run immediately.
1 
1    You should start a script with a tape or disk mounted.  Once you
1 start a script, it prompts you for new tapes or disks as it needs them.
1 Media volumes don't have to correspond to archive files -- a
1 multi-volume archive can be started in the middle of a tape that already
1 contains the end of another multi-volume archive.  The 'restore' script
1 prompts for media by its archive volume, so to avoid an error message
1 you should keep track of which tape (or disk) contains which volume of
1 the archive (⇒Scripted Restoration).
1 
1    The backup scripts write two files on the file system.  The first is
1 a record file in '/etc/tar-backup/', which is used by the scripts to
1 store and retrieve information about which files were dumped.  This file
1 is not meant to be read by humans, and should not be deleted by them.
1 ⇒Snapshot Files, for a more detailed explanation of this file.
1 
1    The second file is a log file containing the names of the file
1 systems and files dumped, what time the backup was made, and any error
1 messages that were generated, as well as how much space was left in the
1 media volume after the last volume of the archive was written.  You
1 should check this log file after every backup.  The file name is
1 'log-MM-DD-YYYY-level-N', where MM-DD-YYYY represents current date, and
1 N represents current dump level number.
1 
1    The script also prints the name of each system being dumped to the
1 standard output.
1 
1    Following is the full list of options accepted by 'backup' script:
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1 '-l LEVEL'
1 '--level=LEVEL'
1      Do backup level LEVEL (default 0).
1 
1 '-f'
1 '--force'
1      Force backup even if today's log file already exists.
1 
1 '-v[LEVEL]'
1 '--verbose[=LEVEL]'
1      Set verbosity level.  The higher the level is, the more debugging
1      information will be output during execution.  Default LEVEL is 100,
1      which means the highest debugging level.
1 
1 '-t START-TIME'
1 '--time=START-TIME'
1      Wait till TIME, then do backup.
1 
1 '-h'
1 '--help'
1      Display short help message and exit.
1 
1 '-V'
1 '--version'
1      Display information about the program's name, version, origin and
1      legal status, all on standard output, and then exit successfully.
1 
1    ---------- Footnotes ----------
1 
1    (1) For backward compatibility, the 'backup' will also try to deduce
1 the requested dump level from the name of the script itself.  If the
1 name consists of a string 'level-' followed by a single decimal digit,
1 that digit is taken as the dump level number.  Thus, you may create a
1 link from 'backup' to 'level-1' and then run 'level-1' whenever you need
1 to create a level one dump.
1