Fuzzy SCSI behavior

[Erichiwaann]

I?m having SCSI problems with the dual CPU, Tyan S1837UANG Thunderbolt mobo (BIOS V2.00.10).

Running Win2k Server, implementing the onboard Adaptec AIC-7896 dual channel Ultra2 LVD SCSI and an IBM Ultrastar 18.3LZX DDYS-T18350 hdd, the system will hang for a few seconds and then resume during normal operations. Sometimes it will require a cold reboot.

I get the following event in the system log:
?The device, \Device\Scsi\aic78u21, did not respond within the timeout period.?

I?ve used a variety of quality SCSI Ultra2 terminated cables and SCSI hdd?s, swapped the PSU and have the same strange behavior.

The Adaptec controller is in default set to SCSI ID 7 and the boot hdd set to SCSI ID 0.

Perhaps it?s a problem with the IRQ arbitration or just a bad mobo? oh well. Got any ideas?

 

[idgaf13]

Is the HDD set to the delay setting ,usually 2 seconds, it may be your problem.
IBM has an excellent tech section for specs concerning their hard drives, you may want to consult it.
also is an excellent resource.SCSIFAQ

 

[Erichiwaann]

Thanks for your help! I'll look into your timing delay suggestion. I'm wondering though, if the active termination has gone bad? Hmmm... I'll pickup a new one and give it a try. The treasure trove of SCSI info is a great link... Thanks again!

 

[Peter]

That sounds very much like a communication failure on the SCSI bus. Check the cable and termination.