R390's and HA Configuration issue

[Michael Covard]

I don't have a diagram to send, so Hopefully this will do.
I have two R390's and 1 HA (Jamaica with 9.1 GB drives).
The R390's each have dual CPU's and one HSC SCSI card (slot 8/8 on one and 10/12 on the other) and one HSC dual lan 10/100 card each.
On the HA I have channel A and B cabled together. The last two connections are to one server and the other to the other server. Addressing on channel B is 15-9 (odd) and channel A is 14-8 (even).
The card address of one HSC is scsi 6 and the other scsi 7.
The issue, when one server (either one) is booted it can see ALL devices. When both are booted, then there are scsi resets happening. Each has a CDrom drive, no tape drives.
The termination is at the cards for each server (termination chips are being used) and I am not using any self-terminating cables.
I am basically setting up a MC/Serviceguard "testing" playground, so I need both servers to see the same set of disk.
ANY help or suggestions would be great!
Thanks,

[Paula J Frazer-Campbell]

Hi Jo
The problem is obviously the HA, am I right in asuming that you wish to see the full disk pack from each machine? Or are you loking at a 50/50 situation.
The scsi controllers are at present both trying to take control of the disk pack and are seeing each other.

What happens if you instead of joining A to B you terminate and fire up both servers.

Paula

[Patrick Wallek]

I would agree with Paula. If you want one machine to see one side of the HA and the other machine to see the other side, then do NOT connect side A to side B on the enclosure. Terminate each side. That should take care of your SCSI resets.

The cause for the resets is probably because both machines can see all the disks and SCSI requests for one machine are being seen by the other machine and each machine is getting rather confused.

If you DO want both machines to see all the disks, then I'm not quite sure what you'd need to do. I don't think that configuration would be suported unless you have an MC/Service Guard environment.

[Michael Covard]

Thanks for the replies.
I think by splitting the A and B bus on the HA would solve the issue but, for MC/Serviceguard "testing" this is necessary for the servers to see all disks.
If the SCSI addresses of the cards are different, this should complete the scsi chain and as long as the scsi ID's of the disks of the HA are not conflicting, there should not be an issue.
Basically sharing disk between two servers.

[Patrick Wessel]

Jo,
SCSI bus resets are always nasty. How long is the cable that connects the A and B channel of the Hass? A short cable can sometimes cause funny errors

[Keith Kalet]

Jo,
This sure sounds like a termination issue. Do you have access to inline terminators for testing? If so, you may want to hook them up just to confirm that the terminators on the cards are working properly. I have the same configuration, but initially we had a problem with double termination. You may have the opposite occurring here. Another couple long shots: Check for bent pins and confirm the SCSI addressing on the Jamaica. Hope this helps.

Keith