Full dumps should only be made when no other people or programs
are modifying files in the file system. If files are modified while
tar is making the backup, they may not be stored properly in
the archive, in which case you won't be able to restore them if you
have to. (Files not being modified are written with no trouble, and do
not corrupt the entire archive.)
You will want to use the --label=archive-label
(-V archive-label) option to give the archive a
volume label, so you can tell what this archive is even if the label
falls off the tape, or anything like that.
Unless the file system you are dumping is guaranteed to fit on
one volume, you will need to use the --multi-volume (-M) option.
Make sure you have enough tapes on hand to complete the backup.
If you want to dump each file system separately you will need to use
the --one-file-system (-l) option to prevent
tar from crossing file system boundaries when storing
(sub)directories.
The --incremental (-G) (see Incremental Dumps)
option is not needed, since this is a complete copy of everything in
the file system, and a full restore from this backup would only be
done onto a completely
empty disk.
Unless you are in a hurry, and trust the tar program (and your
tapes), it is a good idea to use the --verify (-W)
option, to make sure your files really made it onto the dump properly.
This will also detect cases where the file was modified while (or just
after) it was being archived. Not all media (notably cartridge tapes)
are capable of being verified, unfortunately.
Published under the terms of the GNU General Public License
