I've got a client that has an HP SureStore T4 scsi internal tape
backup.  I'm trying to use dump and dd to write the backups to tape and
then restore them for a test.  I've tried setting "obs" and "ibs" in the
command line for the dd call to many different settings, 512, 1024, 1k,
10k, 32k etc..  The result is that I always get an error.   Below is
what is going on.

Using the following settings::
------------------------------
dump 0unf - /etc | gzip -c | dd of=/dev/st0 obs=512
dd ibs=512 if=/dev/st0 | gzip -dc | restore ivf -
------------------------------

When I do a "mt -f /dev/st0 status", I get
------------------------------------
SCSI 2 tape drive:
File number=0, block number=0, partition=0.
Tape block size 512 bytes. Density code 0x45 (QIC-3095-MC (TR-4)).
Soft error count since last status=0
General status bits on (41010000):
 BOT ONLINE IM_REP_EN
-----------------------------------------

I keep getting an error when I try writting the backup to begin with.
This is what happens when I use this command.
-------------------------------------------------------------------------------

[root@mainserver /root]# dump 0unf - /etc | gzip -c | dd of=/dev/st0
obs=512
  DUMP: No group entry for operator.
  DUMP: Date of this level 0 dump: Sun Sep 26 06:43:54 1999
  DUMP: Date of last level 0 dump: the epoch
  DUMP: Dumping /dev/hda8 (/) to standard output
  DUMP: mapping (Pass I) [regular files]
  DUMP: mapping (Pass II) [directories]
  DUMP: estimated 4767 tape blocks.
  DUMP: dumping (Pass III) [directories]
  DUMP: dumping (Pass IV) [regular files]
  DUMP: DUMP: 4568 tape blocks
  DUMP: finished in 10 seconds, throughput 456 KBytes/sec
  DUMP: level 0 dump on Sun Sep 26 06:43:54 1999
  DUMP: DUMP IS DONE
st0: Write not multiple of tape block size
dd: /dev/st0: Input/output error
1957+1 records in
1957+0 records out
------------------------------------------------------------------------------

Now, when I try to use dd and restore for a test, I can see the files
and the sizes and I can move around from directory to directory.  If I
try to do an "add <filename>" for the restore,  it tells me that the
directory that I see the file in doesn't exist.  I can restore a
complete directory if I choose it but not individual files.  Also, I
still get an unexpected end of file error when it is restoring it so it
restores some files, but not all of them.  Do I need to write an EOF at
the end of the file write using "mt" or something?

I know that the tape is working and everything, because I can make the
backup work using tar.  I prefer using dump and dd though because they
are faster and more reliable.

Can someone tell me why I'm getting that error with the dd command in
conjunction with the dump command? As far as I know the "obs" parameter
should be a multiple of the "Tape block size" correct?

Thanks in advance for any help.  I've been tearing my hair out over
this.  BTW, it's running on RedHat 6.0.

C'ya,
Edmund
[EMAIL PROTECTED]

Reply via email to