Backup problems with PV136T Tape Library

Question

We have 2 PV136T LTO(HP) Libraries and have been experiencing drives going offline. I read a recent article and brought that to the attention of my manager who escalated the issue. Since we are a large customer, Dell agreed on replacing the two PV136T Libraries with LTO2(IBM) drives. So far we have had one library replaced and seems to be fine, the other library will be replaced next week.

So word of advice, if you own a PV136T and are experiencing the drives going offline, contact Dell and stress your problems and escalate as far as you can go, the technicians haven't a clue and will ask you to upgrade firmware etc, that does not resolve the drives going offline.

Below are links that support what I have mentioned above.

http://forums.us.dell.com/supportforums/board/message?board.id=pv_tape&message.id=1502

http://mailman.eng.auburn.edu/pipermail/veritas-bu/2002-October/013436.html

http://lists.us.dell.com/pipermail/linux-poweredge/2003-March/023798.html

daddyroo2k · Answer

I know that under windows 2003 there are issues with Plug and play sending out "Test Unit Ready" Commands every second. This applies to tape libraries that are SAN attached only.

Since these TUR commands are sent from every windows 2003 server every second to the tape library it floods the bus causing the scsi bus on the tape library to lock up and fall over. You will generally fine a reboot of the library will bring the library back online, but you follow the same cycle again and again.

There are a couple of ways to resolve this issue....1. look up the microsoft fix for this issue - do a search for "test unit ready"

or 2. Disable plug and play.

If you are a bit unsure of this, the simplest test is to take the tape library out of the Zone that the windows 2003 server are in. If the problem goes away you know that this is your issue.

I will post more info on this soon.

Cheers.

Madaxle

Darren77uk · Answer

Thanks for that, we resolved the issue by installing new Emulex drivers and replacing the Library with a new LTO2 library courtesy of Dell.Â Â Minor detail, the LTO drives were Seagate the drives we currently have are IBM LTO2's.Â Â Everything seems to be fine and dandy, aside from the software we are using which is CommVault.Â Â Powerful but needs tweaking.

Thanks,
Darren

Bill Bradley · Answer

Wow. Deja Vu. We are having the exact same issue, and, were using BUE 9.1, but, are now using CommVault. I know that the Veritas drivers (claim to, anyway) disable TUR, so...since I was still having the issue, feel that it wasn't TUR.

I've done the RegHack in MS KB 842411, so, will see, and, we've had a drive replaced (I have the HP LTO-1 drives), the Power Distribution Board replaced (twice), and, they were going to replace the Picker and Picker Board.

My library would work for awhile, then the lower drive (we have two) would go offline (red LED), and, I'd have to reboot everything. Now...the top drive is doing the same thing.

Sigh...

Thanks.

Darren77uk · Answer

Is it a PV132 or a PV136T? What is the firmware on the drives, are they all consistant? Have you spoken to your dell rep. Perhaps you should point out that Maple Leaf Foods, who I work for had libraries replaced as there was on going problems. Perhaps they will replace your drives. How are you liking CommVault? What version are you on? We are currently running 5.0 and migrating to 5.9 sometime soon.

If you need any help with CommVault would be more than happy to help.

Darren

Bill Bradley · Answer

This is interesting--notice how this message doesn't 'float to the top' of the board, like other new posts. Almost like they're trying to hide it.

Bill Bradley · Answer

It's a PV136T.

Did you even try the RegHack for Windows 2003 to fix Test Unit Ready? The problem with the drive going offline happened even with BUE 9.1 and Veritas drivers, which, supposedly, don't need the RegHack.

I've showed Dell Tech Support this thread, and, hope that they'll take some action--I'm REALLY getting tired of this problem, and their not being able to fix it, so, if they have to replace the whole thing, then, so be it!

Thanks!

Jiflemon · Answer

Hi Guys,   I was looking for some information about disabling TURs specifically with regards to Commvault,and found this thread. looks like you have been through the ringer on this one.   I am a dell tech and have seen TURs make absolute crud out of Veritas, Legato, Comvault, CA ..... you name it (except NT Backup of course).   the problem has got to be one of the nastiest issues I have seen in all my tehnical support incarnations. Chez HP, chez IBM, now chez Dell.   You gotta disable Windows AutoRun on ALL DRIVERS which could be used by Windows to access the drives and the medium changer. You gotta do this in Fibre, and in SCSI hosts (the problem is more noticable in Fibre environments, because more servers are flooding the bus)   If you miss one registry key, you might as well miss them all.   BTW. no amount of hardware changes will resolve the problem. The problem is not particular to Dell either, as every hardware and software manufacturer has to put up with it.   Best of luck...is all I can say

Bill Bradley · Answer

Any reason CommVault, Dell, Veritas, EMC, etc., don't gang up on Microsoft?  After all...if it breaks EVERYTHING, doesn't appear to be a wanted/needed feature...

PowerVault

Backup problems with PV136T Tape Library

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