topic Determining if a vmdk is thin or thick provisioned? in VMware Solutions Discussions

Determining if a vmdk is thin or thick provisioned?

rtriana — Thu, 05 Jun 2025 07:28:49 GMT

Is there a way to determing if an existing vmdk for a vm is thin provisioned or thick provisioned? How do we go about determing it?

Rick

Re: Determining if a vmdk is thin or thick provisioned?

dstrebel — Mon, 27 Apr 2009 19:56:27 GMT

What version of vmware are you using? Thin vmdk's are not a supported feature in VI3.

Re: Determining if a vmdk is thin or thick provisioned?

rtriana — Mon, 27 Apr 2009 20:11:27 GMT

Version 3.5

Re: Determining if a vmdk is thin or thick provisioned?

forgette — Mon, 27 Apr 2009 21:06:47 GMT

Thin vmdk files are supported on NFS datastores as of ESX 3.0. From the service console you can compare the output of the 'ls' command with the output of the 'du' command to tell if the vmdk is thin provisioned.

For example, this file is defined as 20GB, but thin provisioned and only using 92MB:

[root@esx ericXP]# ls -lh ericXP_1-flat.vmdk

-rw-r--r--    1 root     root          20G Mar 26 16:10 ericXP_1-flat.vmdk

[root@esx ericXP]# du -h ericXP_1-flat.vmdk

92M ericXP_1-flat.vmdk

A slightly more efficient way of doing this is to simply add the '-s' option to the 'ls' command:

[root@esx ericXP]# ls -lhs ericXP_1-flat.vmdk

92M -rw-r--r--    1 root     root          20G Mar 26 16:10 ericXP_1-flat.vmdk

In all cases, you want to look at the -flat.vmdk portion of the file pair.

You can also determine this from the VI Client (as of ESX 3.5) by comparing the "Capacity" of the "Hard Drive" in the Virtual Machine Properties window with the Size of the file reported by the Datastore Browser.

Hope this helps,
-Eric

Re: Determining if a vmdk is thin or thick provisioned?

amiller_1 — Wed, 29 Apr 2009 06:27:47 GMT

Thin vmdk's are supported on NFS datastore since 3.0....and do actually work on VMFS as well.

vSphere 4.0 is bringing some nice functionality here as well -- can make a vmdk thin during a storage vMotion.