[comp.unix.questions] dump multiple file systems on same tape ?

olav@nososl.UUCP (Olav Eide) (12/07/90)

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 ?.

   Thanks!


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jxf@altair.cis.ksu.edu (Jerry Frain) (12/08/90)

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.

Try:

	mt fsf n

Where n is the number of filesystems to skip over on that tape.
Do this before you invoke restore. See the man page on mt(1) for
more information.

>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 ?.

Dump always says that it is doing a rewind, even if it is writing to
a device which is not auto-rewind.

  --Jerry

--
Jerry Frain -- Systems Programmer               Kansas State University
                                        Department of Computing & Info Sciences
Internet : jxf@cis.ksu.edu                         Manhattan, Kansas
UUCP     : ...!rutgers!ksuvax1!jxf

gwyn@smoke.brl.mil (Doug Gwyn) (12/08/90)

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..

pjs@euclid.jpl.nasa.gov (Peter Scott) (12/08/90)

In article <84@nososl.UUCP>, olav@nososl.UUCP (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 ?.

At least on my system, I would call the device /dev/nrmt14;
the n stands for "no rewind" (intuitive, huh :-)).  Dump
will still claim that it's rewinding, but it isn't.  You 
can verify the dumps with a sequence of restore ivf; mt fsf
commands.

-- 
This is news.  This is your       |    Peter Scott, NASA/JPL/Caltech
brain on news.  Any questions?    |    (pjs@euclid.jpl.nasa.gov)

shwake@raysnec.UUCP (Ray Shwake) (12/09/90)

olav@nososl.UUCP (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

	You don't specify the system or OS under question. Many systems
support writing without rewinding, leaving only an "end of file" mark, but
not an "end of tape" mark. That tape is then positioned for further writes.
The "no rewind" option is often indicated by an "n" reference in the
device name (e.g. nrct1 vs. rct1, rnmt0 vs. rmt0, etc.) but your system
may follow a different strategy.

ratazzie@lonex.radc.af.mil (Edward P. Ratazzi) (12/10/90)

In article <1990Dec7.185525.14932@maverick.ksu.ksu.edu> you write:
>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.
>
>Try:
>
>	mt fsf n
>
>Where n is the number of filesystems to skip over on that tape.
>Do this before you invoke restore. See the man page on mt(1) for
>more information.
>

Or you can do it all in one step (in SunOS, anyway):

        restore xfs /dev/nrmt8 n

Where n is the file system to skip to (n>0).  

-- 
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