Conversion of thick to thin during vSphere upgrade

[JLogan2016]

I am working with a company that wants to convert all VMs from thick to thin during an upgrade from 5.5 to 6.5U2. I have moved a couple of VMs via a script for testing purposes, and do not see the WEBUI client reporting any difference between the Provisioned Space and the Used Space. I confirmed the VMDKs on the test machines are now thin. Is this expected behavior? Am I only going to be able to see the space savings on the array itself, or is there a way to do so through the Web Client?

[iopsGent]

What process are you following to convert from thick to thin?

[JLogan2016]

Storage vMotion to a VMFS6 datastore as thin.

[iopsGent]

You're running into this VMware Knowledge Base

[JLogan2016]

bleh, I had seen a couple of similar articles, but was hoping (desperately) that I would not have to go down the road of running sDelete on all these machines. It is incredibly difficult in this company's environment to schedule downtime. Thanks for the info

[SupreetK]

Alternatively, use v2v converter to convert the VMs to the destination datastore instead of using SvMotion. While doing so, you can convert the destination disks to being thin. Once the VM is converted, you will have a small switch-over downtime window from the old VM to the new converted VM. Once the converted VM (with disks in thin format) is powered on, you can delete the original thick disks VM. One more advantage of v2v conversion is that you can resize the disks during the conversion.

Please consider marking this answer as "correct" or "helpful" if you think your questions have been answered.

Cheers,

Supreet

[JLogan2016]

Thanks for the suggestion. Unfortunately I don't know that doing a v2v on ~1100 VMs, is going to be something I can get buy in on. I am trying the suggestion in the KB article to create a datastore of a different block size to see if this works.

[iopsGent]

You could try going from an VMFS volume to NFS, you won't be able to change block size.