HP 3PAR - VMware VAAI settings

[glamic26]

Hi Everyone,

I am hoping that someone could clarify something for me. In an ongoing support case with HP 3PAR the engineer has advised us that on ESXi5.5 we should be disabling the VAAI on the ESXi5.5 hosts because the 3PAR OS is 3.1.1 or above and so uses the T10 plugin built in to VMware.

He has provided the "HP 3PAR VMware ESX/ESXi Implementation Guide" which after detailed reading I found has confirmed that the HP 3PAR VAAI Plugin 2.2.0 for ESXi 5.x should not be used on HP 3PAR OS 3.1.1 or later because it uses T10 instead.

That is fine I have not installed this plugin, but I can't find in that document it going on to say that we need to turn off the VAAI in VMware. He specifically wants me to make the below changes:

vicfg-advcfg connection_options -s 0 /DataMover/HardwareAcceleratedMove
vicfg-advcfg connection_options -s 0 /DataMover/HardwareAcceleratedInit
vicfg-advcfg connection_options -s 0 /VMFS3/HardwareAcceleratedLocking

In my mind as a VCP this would disable all VAAI including the built in T10 and I would get no benefit whatsoever. I can't find any other documentation or forum anywhere suggesting that VAAI should be turned off in the way so I can only assume that the HP engineer has made a mistake.

Furthemore the hosts are built with HPs own ESXi5.5 image and so I would have expected that if it was recommended to disable these then it would be done in the image. It isn't, they are enabled by default.

Is anyone been able to confirm which way is correct?

Thanks

Mike

[ascheale]

Hi Mike,

As a VCP and HP Master ASE storage I say let it enabled!
Dont know the reason why it should be disabled.

You are on 5.5 and 3.1.2 or above ?

Greets
Alex

[glamic26]

Thanks ascheale. That put my mind at rest.

Yes we are using ESXi5.5 and 3PAR OS 3.1.2.

[vPatrick]

Hi,

for troubleshooting purposes it can be a good idea to disable VAAI. But there is no reason to disable VAAI generally.

What was the reason for contacting the HP support?

[ascheale]

vPatrick,

you´re right, disabling VAAI for troubleshooting reasons makes sense.

What is the reason for contactin HP support ?

Alex

[Josh26]

Sounds a bit like the old "try disabling jumbo frames" when having issues with an iSCSI SAN.

It's a good troubleshooting step, but that DOESN'T make it a "generally good idea".

[glamic26]

Thanks Guys,

We are having stability issues on ESXi that seem to be caused by one of our 3PAR arrays. HP had advised to turn of VAAI as it was no longer needed as it used VMware's T10. However, after disputing this with them they have confirmed that they just meant not to use the 3PAR VAAI plugin but to leave VAAI enabled on the host to allow T10 commands.

Cheers,

Mike

[vPatrick]

Hi Mike,

yes, disabling the VAAI plugin makes sense. Disabling VAAI doesn't make sense to me, except in some rare cases for troubleshooting.