Rafael072011101
Contributor
Contributor

Thin Provisioning error in disk usage

I'm using ESX 4.1 Up 1. I have a 100GB Datastore. In this install a virtual machine with Windows Server 2003 Enterprise on a single 99GB disk enabling Thin Provisioning.

Now there is something wrong. Once the C: partition had 70GB of data. Of these deleted 20GB of unused information. At the level of windows 99GB disk
has 50GB just busy. But vmfs level appears as if he had even the 70GB used.

Why does not show the same vmfs disk usage status, that the virtual machine windows?

What can you do to have the same state in the VMFS partition and windows. Manual or automatic?

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2 Replies
chriswahl
Virtuoso
Virtuoso

Thin Disk grows in size as needed, but does not shrink. In order to get your 20GB back you'll have to reclaim that space from the thin VMDK.

Easiest way I know of is to storage vMotion it.

Here's a good article: http://www.thelowercasew.com/reclaiming-disk-space-with-storage-vmotion-and-thin-provisioning

VCDX #104 (DCV, NV) ஃ WahlNetwork.com ஃ @ChrisWahl ஃ Author, Networking for VMware Administrators
AureusStone
Expert
Expert

You will need to reclaim that space.  When you delete a file in Windows it doesn't fill the files with zeros, instead the file system just marks the sectors as deleted and allows them to be overwritten.

If you use a utility such as "sdelete" all of your free space will be writen with zeros.  This means if you accidently deleted a file you will not be able to recover it.  Now if you do a svmotion it will reclaim the space.

When you use a utility like sdelete it will actually write to every bit of free space.  As a result the disk will be expanded to the full 99GB before you sVmotion.  Depending on if you have any snapshots or the size of your RAM allocated to the machine you may run out of space on your datastore.