(tar)Multi-Volume Archives

Tape Files

Using Multiple Tapes

Using Multiple Tapes

Archives Longer than One Tape or Disk
-------------------------------------

     *(This message will disappear, once this node revised.)*

   To create an archive that is larger than will fit on a single unit of
the media, use the `--multi-volume' (`-M') option in conjunction with
the `--create' (`-c') option (
FIXME: pxref Creating Archives
   ).  A "multi-volume" archive can be manipulated like any other
archive (provided the `--multi-volume' (`-M') option is specified), but
is stored on more than one tape or disk.

   When you specify `--multi-volume' (`-M'), `tar' does not report an
error when it comes to the end of an archive volume (when reading), or
the end of the media (when writing).  Instead, it prompts you to load a
new storage volume.  If the archive is on a magnetic tape, you should
change tapes when you see the prompt; if the archive is on a floppy
disk, you should change disks; etc.

   You can read each individual volume of a multi-volume archive as if
it were an archive by itself.  For example, to list the contents of one
volume, use `--list' (`-t'), without `--multi-volume' (`-M') specified.
To extract an archive member from one volume (assuming it is described
that volume), use `--extract' (`-x'), again without `--multi-volume'
(`-M').

   If an archive member is split across volumes (ie. its entry begins on
one volume of the media and ends on another), you need to specify
`--multi-volume' (`-M') to extract it successfully.  In this case, you
should load the volume where the archive member starts, and use `tar
--extract --multi-volume'--`tar' will prompt for later volumes as it
needs them.
FIXME: xref Extracting From Archives
   for more information about extracting archives.

   `--info-script=SCRIPT-NAME' (`-F SCRIPT-NAME') is like
`--multi-volume' (`-M'), except that `tar' does not prompt you directly
to change media volumes when a volume is full--instead, `tar' runs
commands you have stored in SCRIPT-NAME.  This option can be used to
broadcast messages such as `Someone please come change my tape' when
performing unattended backups.  When SCRIPT-NAME is done, `tar' will
assume that the media has been changed.

FIXME: There should be a sample program here, including an exit before
FIXME: end.

`--multi-volume'
`-M'
     Creates a multi-volume archive, when used in conjunction with
     `--create' (`-c').  To perform any other operation on a
     multi-volume archive, specify `--multi-volume' (`-M') in
     conjunction with that operation.

`--info-script=PROGRAM-FILE'
`-F PROGRAM-FILE'
     Creates a multi-volume archive via a script.  Used in conjunction
     with `--create' (`-c').