HSZ80 transparent failover problem

[Mike Lievre]

Greetings,

I'm having an issue with two HSZ80's connected in transparent failover mode. I had an alarm from the HSZ80 which I later assumed to be a controller failure as there were no failedsets. I found that one controller appeared to be accessible but the other was not. The accessible controller had the usual reset LED blinking green, while the other's LED was on solid. A software reset of the hung controller was not possible and a hard reset of the other controller also did not register.

I continued by restarting the working controller. The behaviour I experienced at this time is that both appeared to go through the restart sequence and eventually resulted in an alarm. The strange behaviour is that the controller that was hung came back successfully and the other controller then appeared to hang. I could repeat the process switching which controller appeared to be hung, always generating an alarm. I'm not sure if this is default behaviour caused by something or not.

Eventually I took the controllers out of failover mode. At this point a restart of the active controller would result in the same behaviour (it would become hung, the other active) the only difference when this was done in non failover mode is that there was no alarm associated with the restarts and the 'hung' controller would now accept the restart other from the active controller.

Can anyone help me understand what might be happening here? Both controllers appear to communicate with me via the console cable, but only one at a time. While in failover mode each controller also served up disks to the host, but during the long restart disk access was unavailable. It appears that both controllers are functional, but something is preventing them from functioning together simultaneously and I'm not sure what that would be.

Any input is appreciated.

Thanks,

Mike