Alua and Round Robin

[edawg]

Hello-

I have a CX4 Clariion flare 30.x with a variety of production ESX and ESXi hosts connecting into it.  I am thinking of turning on ALUA and changing my pathing to Round Robin to get some of the performance gains I have been reading about.  If you have experience with this process can you comment on 1) Do you really see gains. 2) Any risks to the process that I should be aware of. 3) Comments in general on this.....

Thank you in advance...

[AndreTheGiant]

Note that round robin does not aggregate the different paths...

It only change the path periodically.

So you do not see usually a big improvement.

And if you have more LUNs probably you have already distributed the active paths on the available one.

Andre

[peetz · Accepted solution]

Hi,

ALUA and Roundrobin is the setup that EMC recommends (unless you use their Powerpath for which they promise even more performance).

See here: http://www.vmwareinfo.com/2010/07/how-to-enable-alua-and-round-robin.html

for instructions on how to set it up, and some performance results.

We have set it up without problems, but have not yet done performance comparisons.

Andreas

- The VMware Front Experience Blog

[mcowger]

You wont see a huge improvement in performance, but the gains in not having to manually balance LUNs between controllers and small performance benefit of decreased queue depths can help.

Its also EMC's recommended best practice.

(disclosure, I work for EMC).