multipath behavior

[David P Lavoie]

Good day,

Running HPUX 11.31 on rx6600 with EVA 6100 connected on a director switch divided into 2 fabrics. 2 HBAs are connected on the SAN with 1 port connected to each fabric per HBA.

When I disconnect on the server the 2 ports connected on fabric A, the lun is not accessible anymore. Only 4 paths per lun are presented. Plus, the load balancing doesn't use the 2nd controller on the SAN. The policy currently in place is least_cmd_load.

I've run the command "fcmsutil /dev/fcdx get remote all" on each port and they all see the same thing (ctl plus ultrium 4 tape) so zoning is not an issue. Results are attached to this thread.

Before the change, all luns were showing 8 paths. I tried to present another lun and got 4 paths again. ioscan, insf -e and reboot don't change a thing. Running ioscan shows all paths to luns on eva are presented only under 2 ports. Any ideas why the fabric B is not used at all?

Is it normal that HP UX is only using one controller while copying files on the SAN?

I must add that the director switch was divided after lun presentation to the server. But presenting a new lun gets the same problem too.

[David P Lavoie]

We found the problem. There was a step that was forgotten by our san admin in commandview. Before splitting the director switch into 2 fabric, commandview was presenting the backup on 2 ports and the luns on other. That wasn't changed afterward.

So basically, even if the luns were presented to the hosts, only 2 ports were allowed to see them in commandview.