topic Re: Symm LUN path in Operating System - HP-UX

Symm LUN path

David J Brown — Tue, 27 Nov 2007 15:58:05 GMT

I am observing a situation where a server in HP-UX 11i is connected to an EMC symm via dual HBA's. The odd part is of the 20 or so LUNS assigned, some are showing two paths (the correct config), some are showing 1 path and a couple are showing 3 paths. I'm curious as to how a server with only two HBA's installed could somehow think it has 3 paths to a LUN? If it matters, PowerPath is not currently installed on this server and PVlinks is enabled.

Re: Symm LUN path

Sandman! — Tue, 27 Nov 2007 16:32:51 GMT

Proper fabric zoning has a lot to do with alternate paths besides the dual HBAs which should show two paths per LUN. Check with your SAN team if they have zoned it correctly. Also attach the output of ioscan here:

# ioscan

Re: Symm LUN path

Geoff Wild — Tue, 27 Nov 2007 16:59:30 GMT

Easy - I have 2 HBA's - but 4 paths.

We have multiple Brocade switches in our fabric - the 2 that my HBA's go tt each have a connnection to a FA on the DMX. - There's the 4 path's.

As to why you have 3 and 1 - sounds like a SAN issue to me - IE - they didn't zone it correctly....

Rgds...Geoff

Re: Symm LUN path

TwoProc — Tue, 27 Nov 2007 18:39:18 GMT

2 HBAs going into two ports on a SAN switch. That's 2 paths. Let's also say that there are two ports going out from the switch to a storage device, that's FOUR paths.

So, it's 2HBAPaths X 2StoragePaths = 4 paths.