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March 31, 2010


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Vaughn Stewart

Chad - Great data, thanks for sharing. I would share that these results closely resemble what we have seen with our in-house testing, which is to say the difference in the EMC reported performance results 8.4%.

Look at the results in a relative relationship with the highest value representing 100% obtainable I/O
PP/VE = 100%
NMP RR default = 91.6%
NMP RR 1 IOP = 96.6%
NMP RR 1496702496 = 98.3%

I would suggest that vSphere customers should feel very confident that NMP can address their most demanding workloads, wouldn't you agree?

Chad Sakac

@Vaughn - I would say that NMP RR is excellent, and a great choice. PP/VE is better.

This workload didn't drive network or HBA congestion, have a high degree of random variation in the workloads and IO sizes from the guest, or target array port congestion - those are all the things where adaptive/predictive queuing is better. Creating that kind of test harness is difficult, but not impossible. Conversely, that's exactly the day-to-day at a large scale customers all over the world.

Lab tests tend to be relatively "clean". The real world is messy.

Also, the key is that PP/VE doesn't just change the PSP (path selection plugin) behavior, but the SATP (Storage Array Type plugin) behavior. Things like automated path discovery, proactive path testing (even in periods of no IO), the bigger you are, the more important those operational/manangement things are.

Look, that's not to pooh-pooh NMP RR, EMC supports it, embrace it, and it's free. If you look, there are boatloads of "free in the box" optimization in the native, free SATP around EMC platforms (along with others) - results of work between the engineering teams.

Like I've said: "NMP in the past = no so good, NMP in vSphere with RR = better; PP/VE = best" PP/VE is also not free.

Thanks for the comment!


Any testing allready done with VNX and vSphere 5 on this?

Also the full whitepaper you refer to on Powerlink does not include test results of other NMP tests, would be great to see graphics also on the others.
One other thing that I was wondering about: the test in this post refers to 4x FC HBA ports, but the esxtop VMware output in the whitepaper only shows 2x FC HBA's in use... Are you speaking about the same tests?

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