Brent,
Have you tried listening to the tape drive as it works? Is it for
instance, writing for a bit, then stopping, backing the tape up, then
writing some more?
Modern tape units 'stream': that is, they manouver the tape back to well
before the end of the last write, wind the tape up to speed, and start
writing whne they pass the appropraiet tape mark. If you keep the
buffer full, it streams at full speed and all is well. If the buffer
gets empty, it has to stop and wind back, then start again. The
start-stop is usually clearly audible.
So if it is doing start-stop, two guesses: either your box is doing
something else while the backup is going on, and this renders it unable
to keep the buffer full, OR, the tape heads need cleaning: dirt can
cause all sorts of weird problems.
You may also see errors in the SCSI transport layer (/var/log/messages)
if the tape drive is ailing. SCSI bus resets and the like. If so,
check the cable first.
Regards,
Martin.
--
-------------------------------
Martin Bly
RAL Tier1 Fabric Team
-------------------------------
> -----Original Message-----
> From: [EMAIL PROTECTED]
> [mailto:[EMAIL PROTECTED] On
> Behalf Of Brent L. Bates
> Sent: 20 April 2007 21:54
> To: Scientific Linux Users mailing list
> Subject: Problems with Tape Backups - Continued
>
> I tried backing up to a file instead of the tape drive
> in order to see if I could narrow down where the problem is
> located. It completed the full backup of 27GB in 1618
> seconds (27 minutes). I used xfsdump to do it. This would
> indicate to me that there isn't anything wrong with the file
> system or any problems with large sparse files as others
> suggested I check. Since that worked with out problems, it
> would seem to me that the real problem is with the tape drive
> connection. I've already tried a couple of different tapes
> with out any luck. Could it be the drive itself? Anyone
> have any other ideas for me to check out? Thanks.
>
