SCSI Bus Reset Over Fibre Chanel

[Claude Legare]

It is a fact that Tru64 and Microsoft Clusters géenerate SCSI Bus Reset for ressources reservation. My problem is that those Bus Resets are sent over Fiber chanel and reach the tape devices and then all running backups stops an tapes are rewinded and marked as full.

My config is dual Fibre chanel (with three Sanswitch EL each) with Modular data router. Libraries are Storagteck L20. Storage is on MA8000. All driver and firmware are up to date. I use WWN zonning on switch and mapping presentation on MDR. Is there a way to stop SCSI Bus Reset reaching tape devices? Maybe at the MDR level? We plan to replace the MDR with an NSR for performances and we wish that it will help us.

Thank you for your answers. Claud

[Marino Meloni_1]

there is the usuals thinks to check on the Microsoft servers, I do not know Tru64.

Usualy RSM should be stopped and disabled on w2K servers, if you run w2k3, you have to start and then stop the service (RSM) or it will run in background some component even if you stopped it.

you should also stop insight manager agent for scsi and Fibre channel if active, they can cause problem in certain circonstances.

you have to stop any SAN monitoring tool that can interfer and see if problem disapear.

these tips are usualy applyed when you have backup disruption or drive reservation conflict.

Now related to scsi bus reset, this can be caused also by hardware problem.

[Fernando Bandeira]

Hi Claude,

As far as I know, if you put each server on tha SAN that can see the tape library into its own backup zone, it should solve the problem.

Regards,

Fernando

[Claude Legare]

I Marino,
I kew about RSM and everything is under control. Insight manager is not running and monitoring tools are not running when bus resets happen.

I Fernando,
The zonning is alredy that way.

The bus reset happen when a Microsoft cluster node reboot. Now, we didn't test it again but it seems that the latest driver for HBA FCA2201 use the Storeport of Microsoft 2003 that is suppose to send bus reset for devices reservation, directly to the disk drivesand not to the tape drives. We have to test that.

But for tru64, I haven't seen anything to controle thoses resets.

Is there a way to filter SCSI Bus Reset?

Regards,
Claude