Confusing datastore browser display, thin vs thick, size vs provisioned

[fajarpri]

Hi all,

ESXi 4.1

This is very confusing.

The case is:

A VM is setup with 50GB Thin HDD.

1). In the datastore browser, the display is:

Size: 11GB

Provisioned size: 50GB

2). From SSH, the file size of the vmdk is 50GB

So my question:

1). What is the actual space usage of the VM? 11GB or 50GB?

In my understanding, since it is Thin provisioning, it should be 11GB. But why SSH shows it 50GB?

2). Why on VM with Vista, there is no "provisioned size" column in the datastore browser?

Thank you.

[piaroa · Accepted solution]

If you used thin disks, the used space in your example is 11GB.

[MauroBonder]

check http://kb.vmware.com/selfservice/microsites/search.do?language=en_US&cmd=displayKC&externalId=100541...

and http://www.vmware.com/pdf/vsp_4_thinprov_perf.pdf

[fajarpri]

Thanks for the PDF, it is really helpful.

But, this paragraph gives doubt:

"In order for a guest  operating system to make use of a virtual disk, the guest operating  system must first partition and format the disk to a file system it can  recognize. Depending on the type of format selected within the guest  operating system, the format may cause the thin provisioned disk to grow  to a full size.

For example, if you present a thin provisioned  disk to a Microsoft Windows operating system and format the disk, unless  you explicitly select the Quick Format option, the Microsoft Windows  format tool writes information to all of the sectors on the disk, which  in turn inflates the thin provisioned disk."

So, when we INSTALL Microsoft Windows, will it make THIN to THICK?

Hmm.. wait, I'll re-read the PDF again

[mittim12]

I just created a R2 template not to long ago and it was still thin after the install.  If something did accidently become thick you could always zero out the free space and storage vmotion using the thin option.  That would turn it thin again.  

[fajarpri]

Ok, I confirm that for THIN, the SIZE column is the actual usage of the space. PROVISIONED is the size of the virtual disk.

ls -lh
-rw-------    1 root     root         4.0G Mar 17 08:02 Srv-f62ec53b.vswp
-rw-------    1 root     root        50.0G Mar 24 01:48 Srv-flat.vmdk

du -h *.vmdk
10.5G   Srv-flat.vmdk
64.0k    Srv.vmdk

Thank you very much for the help. This also confirm that installation doesn't make THICK disk in Microsoft OS.