Limiting clone IOPS

[kdct]

Hello all,

When doing a clone in my environment, our EMC array's CPU jumps to 80%+ which impacts other VM workloads during the clone. It didn't used to do this, but as we've grown it gotten worse. Do you know if limiting the IOPS on the VM to be cloned will limit the clone operation as well? I ask because when you do a clone, the task runs against the storage cluster- not the VM (possibly because it's using VAAI?)

Any tips or recommendations?

[bryanvaneeden]

If it's running VAAI (hardware accelleration), the cloning operations will be offloaded to the storage array, which should be fast. But it does give the array more to do, which might explain the jump in load.

Maybe in your scenario you are better off disabling VAAI. You can do this on one test host to check if this helps. Have a look here for disabling VAAI: https://kb.vmware.com/s/article/1033665 

I'm not sure if limiting the IOPS on a disk will also limit the IOPS during cloning, to my knowledge this won't be limited.

[scott28tt]

@kdct 

Moderator: Moved to Storage Performance

[depping]

it has been a while since I looked a this, but I am pretty confident that it still applies, SvMotion and Clone operations are not billed to the VM, which means the limit would not apply to those processes. (http://www.yellow-bricks.com/2018/07/11/vsphere-6-5-and-limits-do-they-still-apply-to-svmotion/)