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From: gwyn@smoke.brl.mil (Doug Gwyn)
Newsgroups: comp.unix.questions
Subject: Re: dump multiple file systems on same tape ?
Keywords: dump,filesystems
Message-ID: <14688@smoke.brl.mil>
Date: 7 Dec 90 20:28:43 GMT
References: <84@nososl.UUCP>
Organization: U.S. Army Ballistic Research Laboratory, APG, MD.
Lines: 28

In article <84@nososl.UUCP> olav@nososl.UUCP (Jan-Olav Eide) writes:
>I am attempting to dump several (root) filesystems onto the same tape,
>using the following syntax:
>   dump 0ufsdn /dev/rmt14 10000 1500 /dev/gd0a
>   dump 0ufsdn /dev/rmt14 10000 1500 /dev/gd2a
>   dump 0ufsdn /dev/rmt14 10000 1500 /dev/gd4a
>The dump proceeds nicely, but when I attempt to restore, all I find
>on the tape is the first filesystem. No sign of the two other. 
>Dump also informs the that it is rewinding the tape after each
>dump, but the time this takes is much too short for that to actually
>happen. /dev/rmt14 does not do an automatic rewind. I have not found
>anything in TFM to enlighten me, maybe anyone on the net can ?.

While the files are probably all present on the tape, they should be
separated by tape marks.  Worse, it sounds like "dump" is closing the
device, which should write TWO tape marks and if you are unlucky may
leave the head positioned after the SECOND tape mark (after the FIRST
would be proper behavior).  What all this means is that when restoring
from the tape, an "end of file" will be encountered whenever a tape
mark is read.  Probably the restore procedure is too dumb to cope with
multiple files on the tape, and I would bet that it doesn't even
advance to the first end-of-file when it thinks it is finished with
the first dump file.  Perhaps you can keep telling it to continue using
the same device (with the tape left in position), and if you're lucky
it will eventually get past the tape mark or two and see the next dump
file.

Good luck..