Clariion FC4700 & LVM alternate paths

[Stephen Hearn]

Hi - have L-class (5470?) attached to EMC Clariion FC4700 dual SP's via dual HBA's over fibre SAN. Fully redundant connections thru fibre switch. We had some filesystem corruption apparently due to a problem with one of the SP's. EMC can't explain why alt path to other SP was not used & corruption avoided. LVM alt path has been setup. Their theory is that we are not using the correct device (there are four device paths - 2xSP's x 2xHBA's) for LVM alt path to LUNs. But LVM does not recognise the other devices as alternate paths. Has anyone got a similar setup & managed to get full HBA/SP redundancy going? HP-UX 11.0 patched to 9/02.

cheers
steve

[Wayne Willess]

Steve, EMC might be right. You could have set the primary path to port 0 and the alt path to port 1 of the failed SP. Check you hardware paths on your HP system. Here is an example from one of my HP systems.

0/6/2/0.8.0.1.0.2.1

The last four numbers identify the path to the LUN. (1.0.2.1) The first number is the SP ports the second and third numbers are the DPE/DAE enclosure and the fourth is the LUN number on the enclosure. The SP ports are numbered 0-3 with SP-A being 0 and 1 and SP-B being 2 and 3. If your primary and alt paths were pointing to 0 and 1 or 2 and 3 then you had them pointing to the same SP.

Hope this helps.
Wayne