VMWare Migrate.DiskOpsEnable for Nimble... set to 0 or 1?

[navyboy125]

In a standard deployment of VMWare ESXi hosts under advanced settings there is a value called Migrate.DiskOpsEnabled and by default it is set to 0 (ZERO).

My question is for a Nimble array (CS460G-X2) should this setting be set to 1 or 0? 

My understanding is that this switch allows SCSI commands to be offloaded to the Array to perform the work rather than operating over the VMotion network.

If there is a clear answer on how to set it to 1 or 0 please let me know.  If there are different scenarios in which you want it set a certain way, please let me know the criteria to look for to answer if it should be set to 1 or 0 based on our environment.

[wen35 · Accepted solution]

Hi Sal Bonaccorso, I'm bringing this up w/ our engineering team, as well as reaching out to VMW to obtain exact definition.  Is there a reason why you are looking to enable this option? 

As for block copying offload - that'd be the XCOPY VAAI primitive.  That primitive is currently targeted for a future release of Nimble OS.  We have customers leveraging the array zero copy clone option to speed up VM cloning, without taking up additional space.

Hope this helps.

-wen

[navyboy125]

Yes we are seeing poor performance when vmotioning between Volumes. So I was hoping the hardware offload would help. It helped a little, but not much.

Sal Bonaccorso

IT Advisor

CALPINE CORPORATION

Direct: (713) 830-2021

Email: salvatore.bonaccorso@calpine.com<mailto:salvatore.bonaccorso@calpine.com>

[wen35]

Has it always been slow or just got slow recently?  Is your vMotion network dedicated or shared?

[navyboy125]

Dedicated. Always been slow. Was on an EMC array but hoping the nimble would be faster.

Could be our vmotion network settings, will contact vmware.

Sal Bonaccorso

IT Advisor

CALPINE CORPORATION

Direct: (713) 830-2021

Email: salvatore.bonaccorso@calpine.com<mailto:salvatore.bonaccorso@calpine.com>

[wen35]

Feel free to contact our support team to double check data in infosight for your array, to make sure everything is healthy.

Have you tried looking at the esxtop stats for your vMotion NIC?  look for throughput & transmit/drop packet stats.  More details in this article here: CLI madness part I – performance health check for ESX in 5 minutes | super sonic dog (S.S.D)

[navyboy125]

So set it to 0