Disaster Recovery - Block Size issue

Question

I have tried to perform a 'DRP' for our company at a completely cold site. No connection back to our office at all. We are running MS Windows 2003 R2 at the office with NetWorker 7.3.3. At the DRP site we are running IBM Xseries 345 server attached is an TS3200 LTO4 Tape Library. The SCSII card is an Adaptec 39160. Note that we also using a single IBM LTO3 Tape drive (3580). Both Tape library and single tape unit produce the same 'block size' error = 'fn 2 rn 0 can't read The parameter is incorrect No bootstrap found' We've attempt to resolve the issue by using different drivers (old and new), checked SCSII settings and have found that the default 64Kb block size can not be changed to accodate the 128Kb block size on the backup media. We have scoured the forums and internet for solutions, none of which have helped so far, with the error message remaining the same. We even added the following line to the MS Server Environment Variables: NSR_DEV_BLOCK_SIZE_LTO_3=128 but this has not helped (yes - we have rebooted the server) Could someone please advise if they have any other ideas or how to correctly add the BLOCK SIZE command for LTO-3 or LTO-4 and which startup file this line should be added to?

ble1 · Answer

I find a bit strange that you are limited to 64KB. Your variable won't help here as it is not NW that is limiting you. Actually, default bs for LTO4 is 128 by NW so setting this again from env is pretty much useless. Best results you get with 256KB, but you must first fix your 64KB issue. You may wish to force 64KB read on device, but I'm not sure if that is going to help you (check device properties) and of course you wish to see which component is stopping you from having bigger bs (OS, SCSI cars, etc). I remember 2003 SP1 has this problem and MS had to come up with patch to fix it...

andreas.scht · Answer

Hello!The problem is that Microsoft changed the default tape block size to 64KB in Win 2003 SP1. This size is fix now and could not be changed by using MaximumSGList registry key.German article which describe the problem:ftp://ftp.legato.com/pub/NetWorker/German/ntgen_67.pdf

ble1 · Answer

... or simply look for 907418 in this forum (or MS support page). However that would be the case only if you have SP1 (2003 R2 is a bit cryptic to me as I do not come from MS world).

EDL001 · Answer

Update - we are running MS Server 2003 Standard Edition SP2 at the DR site. A mistake on my part, but by going on all the internet chat SP2 fixed the 64Kb problem in SP1.

Maybe we need to run 2003 R2 to fix.

ble1 · Answer

Yes, SP2 does fix this issue. DR site should run the same OS as original site do having R2 there might address your issue.

NetWorker

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