Internal DAT drive backup errors

[Ayman Altounji]

Using 20/40GB DAT Internal DAT drive (no firmware revs found on Compaq support), Arcserve 6.6 SP4. multiple SCSI bus errors during backups.
At approx. 3GB backed up (100-200KB/M), the backup fails with various SCSI communication errors. Server will hang, Arcserve cannot be unloaded and often the job cannot be stopped. The serve must be rebooted. (3) servers involved. One had hardware errors on the tape drive LCD from the start. One showed errors, but with slight driver adjustments completed backup of 3.1GB correctly. One has failed 3 backups started after a fresh reboot. Once the error occurs, any new backup jobs have SCSI communication problems and the server eventually hangs or abends on backup thread or during the unload of the device driver. Restores do not have this issue, but they are also slower. Using HP old and new DDS-3 tapes in drive with autoloader. Backup requires multiple tapes because of size. Using on board SCSI bus.
Is there a known Compaq issue with bus/controller/driver speeds vs. the slowness of tape drive hardware?
Thanks for a speedy reply.
A. Pouliot

[Ayman Altounji]

I have an ML530 with an external HP 14/24 DAT 4mm. I am using BackupExec 8.5. I have very similar problems with hangups and failed backups. Based on my investigation of the various errors, I think I have narrowed it down to a conflict or incompatibility between the 5300 controller driver and the open file agent. It is very frustrating. Your backup software is different, and your tape drive is different, but your description of your problems are nearly identical to mine. Makes me really wonder what is going on.

[Ayman Altounji]

I am using Arcserve2000 with SP2 on NT Small Business Server 4.5 and experience the same SCSI errors with my 20/40 8AL drive. Have had all the hardware in the SCSI path replaced and updated all drivers. Last night I backed up using NTBackup just to prove to CA that Arcserve is the culprit and I got no errors. CA have suggested I decrease SCSI transfer rate to 20 however I can't find this in the BIOS.

[Ayman Altounji]

I am having similar problems w/ Arcserve 6.6 and 2000. My backups seem to work okay but restores and verifys give me a SCSI timeout error. My next step is to try NT's backup to see if it is a problem with Arcserve or the drive itself. This is a new server that we are trying to get setup.

[Ayman Altounji]

An update on my progress. NT backup works 100% of the time for us. Turning off the Open Files Agent in Arcserve didn't resolve the problem. CA are following up with Compaq to see if there are incompatibilities between the ML530 hardware or drivers and the Arcserve software itself. CA suggested trying a separate SCSI card rather than the onboard card but I don't have one to try. Do any of you have a separate SCSI card you could try?