Adding a drive to a Jamaican Enclosure on a J210.

[Jack Long]

I recently attempted to add a 4-gig disk drive (previously used from another system) to a Jamaican Enclosure that is daisy-chained to an external HP 6000 enclosure on a HP J210 running HP-UX 10.20. The two enclosures are on hardware path 8/0. Using 'ioscan -fnC disk', I determined that there were available scsi id's at paths 8/0.0 and 8/0.3. I set the jumpers on the back of the enclosure and plugged in one drive and got the following message as indicated on the attachment.

I immediately removed the drive and got similar output again (see attachment). The server is fine, but I need someone to tell me what happened. I tested this drive and several others in a test enclosure before and after the event and the drive never caused results like this even though the test setup is similar to production. Any ideas?

[Eugeny Brychkov]

First of all make sure that drive you're inserting is of the same type as already installed ones - yellow SE is for single-ended and pink DF for differential. Then recheck SCSI Ids at the back of enclosure again - I'm not sure but feel that they could be set in negative manner (like 1=off and 0=on). Just check which drives are already on the bus and match their switches to understand how to set this new slot SCSI Id.
Generally, when you plug drive into loaded system and at this time system accesses bus then data on the bus got corrupt and NCR chip (SCSI controller) issues reset to clear erroneous condition. So if you insert this drive and see 1-2 these resets and no more than it should be ok. If you see them a lot continuously accumulating in syslog - then there's a problem
Eugeny