Duplicate to tape job stops writing after 50ish gb

[tolian49]

We're evaluating moving from 10d to 11d on our existing setup.  However, the new 11d, with all 5 patches via liveupdate done, hangs when the duplicate job is running.

We first backup our network -- approximately 220gb including 1 exchange server, to an MD3000 disk array.  This job completes successfully in about 4 hours as expected.  Then the duplicate job kicks off and runs great, about 1gb/min for an hour, but once it gets to 5100 or 5200mb or therabouts the job stops writing.  It sits at the same byte count, and the mb/min drops minute after minute.  About 4 or so hours later I've gone ahead and stopped the job.

I've tried adjusting the resource order of the main backup itself to see if that made a difference in the byte count (it was doing exchange first originally), but that didn't seem to have any effect.

We're using a new Dell 2950 server with MD3000 SAS attached.  The tape library is a Dell 122T with an Ultrium LTO-2 drive.  We're using Windows Server 2003 x64.  The scsi controller for the Dell is an Adaptec 39160.  I've already modified the registry with the fix here: http://support.microsoft.com/kb/897346 that was causing the tape drive to write at a whopping 100mb/min for days on end w/o finishing.

Also I've noticed that the media reporting back is weird inside of backup exec.  These cartriges should be reporting 200gb, but they all read 17.8gb.  Then once a job has run with its 50gb on it the tape will read 3.81/17.8gb used and a compression ratio of like 12.7:1, which is obviously off, although the 12.7 ratio * the 3.81 used does equal out the 50 total.

My current testing is that I'm going to see if it can write more than 50gb if I just do a straight backup job to tape -- for the sake of trying, but that won't do anything to fix the duplicate problem unfortunately.

Any help would be greatly appreciated, this is becoming very frustrating!

EDIT: hardware compression is enabled on the job

Thanks,

Nick

Message Edited by tolian49 on 10-08-2007 07:39 AM

[Ben_L_]

Nick,

What drivers do you currently have loaded for the tape drive?  If the provider is not Symantec, I would suggest updating them to the latest drivers, run an inventory on the library and attempt the duplicate or backup again.

[tolian49]

Well after all I think I've gotten it resolved.  It does look to have been a driver issue with the tape driver.  I had installed BE 11d with telling it to use symantec drivers, however when I ran tapeinst it found my ultrium drive and changed its driver.  I restarted and last nights duplicate ran to completion.

Whats very curious for me about the whole thing though is that the backup test job I ran yesterday that went straight to tape and was not a duplicate job ran to its completion without error.  It seems strange that a backup job would be okay, but a duplicate job would fail after x bytes written.  Is there a fundamental different in the methodology the tape drive uses when doing a duplicate vs a straight backup job?

Thanks,

Nick

[Ben_L_]

Is there a fundamental different in the methodology the tape drive uses when doing a duplicate vs a straight backup job?

Not that I am aware of.