Multi-Pathing for VMware ESX Environments Running on EVA8100

[fh-djb]

I'm looking for some advice or best practices on configuring multi-path settings with ESX hosts. Can anyone tell me what they are doing or point me to an HP guide that has some suggestions?

Any help in this area would be much appreciated.

[Rob Leadbeater]

Hi,

There isn't normally much that needs configuring, as the multi-pathing is built in to the VMware kernel...

Are you having particular problems that you're trying to resolve ?

Cheers,

Rob

[fh-djb]

No problems with the way we have everything setup. We do not have a virtual infrastructure that is taxing the array. Currently we have *all* VMOS vDisks/LUNs set to No Preference and they are *all* using controller A as the primary. Perfmon data is showing that with all our production vm's the EVA's are not really being pushed (average read/write latencies hover between 20 - 50ms during peak activity).

As the virtual environment grows over the life of the EVA's (4 more years) we may at some point need to address performance tuning with multi-pathing tweaks. Wanted to be prepared now for future events.

[Uwe Zessin]

> they are *all* using controller A as the primary.

That is because the EVA-8100 is an A/A/A storage array and, as far as I can tell, VMware ESX does not understand what a non-optimized path is so it uses the first active path it has found.

No path-preferrence setting on the EVA will change this - if the traffic to a virtual disk is high enough, the EVA will even transfer the ownership to controller A to bring the processing 'near' the host.

To work-around this, you do need to change the active path on all members of the ESX cluster with the VI client or the 'esxcfg-mpath' command. If you don't set this up consistent, you might see VDisks flipping between controllers.

[fh-djb]

Also, multipathing is *not* built into the vmkernal.