topic Load balancing on FC HBA in Operating System - HP-UX

Load balancing on FC HBA

MohamedTaher — Fri, 03 Oct 2008 10:14:46 GMT

Hi,

We have many storage virtual disks presented via 2 SAN switches to a RP4400 running HP-UX 11.11 and using 2 FC HBA (each HBA connected to a different SAN switch)

Because of performance issues, we installed in the server 2 new FC HBA, so we have in total 4 new FC HBA (2 HBA connected to the same switch.

The question is how to implement load balancing on the four FC HBA to increase performance, and this for:

- Volume Groups contaning lvols using one PVG with strict allocation policy

- Volume Groups without PVG and strict allocation policy

Re: Load balancing on FC HBA

Rita C Workman — Fri, 03 Oct 2008 10:59:17 GMT

You probably have pvlinks on the box, but that really doesn't load balance. More like failover to other HBA if one goes down.

You could install software that allows for more verbose load balancing - SecurePath is the HP product. We're an EMC storage shop, so we use PowerPath for load balancing.

When you get to 11.31 it seems that SecurePath is part of the kernel - but that is for another thread.

Just a thought,
Rita

Re: Load balancing on FC HBA

Duncan Edmonstone — Fri, 03 Oct 2008 11:59:24 GMT

Some clue as to the sort of disk array you have would help here... You almost imply that this is an EVA of some sort without explicitly stating that...

HTH

Duncan

Re: Load balancing on FC HBA

MohamedTaher — Fri, 03 Oct 2008 12:04:27 GMT

yes that's right it's an EVA ;-)

Re: Load balancing on FC HBA

Tim Nelson — Fri, 03 Oct 2008 14:55:44 GMT

Then secure path is what you need to purchase.

With out it your only option is to manually round robin the pv-links/alternate paths.

On my older systems without any secure path I stagger the primaries over all 4 paths.

e.g.
dev1 on path1
dev2 on path2
dev3 on path3
dev4 on path4
dev5 on path1
dev6 on path2
etc..

If you wish to be more effective then monitor the io usage of each of your lvols and balance that way and review on a weekly/monthly basis. Something is better than nothing.