tar: Full Dumps

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1 5.1 Using 'tar' to Perform Full Dumps
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1      _(This message will disappear, once this node revised.)_
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1    Full dumps should only be made when no other people or programs are
1 modifying files in the file system.  If files are modified while 'tar'
1 is making the backup, they may not be stored properly in the archive, in
1 which case you won't be able to restore them if you have to.  (Files not
1 being modified are written with no trouble, and do not corrupt the
1 entire archive.)
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1    You will want to use the '--label=ARCHIVE-LABEL' ('-V ARCHIVE-LABEL')
1 option to give the archive a volume label, so you can tell what this
1 archive is even if the label falls off the tape, or anything like that.
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1    Unless the file system you are dumping is guaranteed to fit on one
1 volume, you will need to use the '--multi-volume' ('-M') option.  Make
1 sure you have enough tapes on hand to complete the backup.
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1    If you want to dump each file system separately you will need to use
1 the '--one-file-system' option to prevent 'tar' from crossing file
1 system boundaries when storing (sub)directories.
1 
1    The '--incremental' ('-G') (⇒Incremental Dumps) option is not
1 needed, since this is a complete copy of everything in the file system,
1 and a full restore from this backup would only be done onto a completely
1 empty disk.
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1    Unless you are in a hurry, and trust the 'tar' program (and your
1 tapes), it is a good idea to use the '--verify' ('-W') option, to make
1 sure your files really made it onto the dump properly.  This will also
1 detect cases where the file was modified while (or just after) it was
1 being archived.  Not all media (notably cartridge tapes) are capable of
1 being verified, unfortunately.
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