topic Re: vmdk disk format in VI: VMware ESX™ 3.5 Discussions

vmdk disk format

fordian — Fri, 14 Sep 2007 16:36:54 GMT

Hello,

When creating a new vmdk how can I see the disk format (zeroedthick or eagerzeroedthick or thick) on a vmfs3 volume ?

Thank you

Dominic

Re: vmdk disk format

oreeh — Fri, 14 Sep 2007 16:44:38 GMT

The default option is always zeroedthick.

If you want to create other disks you have to use vmkfstools.

Re: vmdk disk format

fordian — Fri, 14 Sep 2007 17:00:01 GMT

but how can I see the it after the creation of vmdks ?

Re: vmdk disk format

oreeh — Fri, 14 Sep 2007 17:01:56 GMT

You can only distinguish thin and thick disks (simply by looking at the size of the vmdk file).

I'm not aware of any method to distingish for example zeroed and eagerzeroed disks.

Re: vmdk disk format

fordian — Fri, 14 Sep 2007 17:44:41 GMT

I did not find anything.

I hope someone knows \!!!

Thank you

Re: vmdk disk format

oreeh — Fri, 14 Sep 2007 18:20:02 GMT

I just tried it

The only indication is

ddb.thinProvisioned = "1"

in the descriptor if it is a thin disk.

Eagerzeroed, zeroed and thick disks have the same descriptor.

Eagerzeroed and zeroed disks (of the same size) even pass a binary comparison.

Thick disks of course don't pass the binary comparison due to their nature.

The only logical answer to me is that part of the CID value distinguishes them.

Re: vmdk disk format

DonalB — Sat, 20 Oct 2007 12:39:48 GMT

Have been trying to find this out myself for a while, found this post http://communities.vmware.com/message/501161, which helps to some degree. Use the -s option with ls to see the block size so

ls -lh <vmdk path>

should show the size reported by the file and compare this to

ls -1sh <vmdk path>

and of it's smaller than the first value then it's a thin disk

Cheers