Used Space Calculation on a VMware NFS Volume

[CLOUDMINER]

I have a VMware VM that is thin provisioned.  It is the only VM on a NetApp NFS datastore.  (The NetApp volume itself is thick provisioned)  In vCenter, provisioned space for this VM is 100GB, but used space is only 50GB.

The NetApp Volume is 1TB.  From the NetApp perspective, this volume's "provisioned space" is 1TB. 

What will NetApp report as the "used space" for this volume. 100GB or 50GB?

[jonathon_lanzon · Accepted solution]

The used space in your 1TB volume should be around 50GB.

If the VM is only comsuming 50GB of space to provide a thin-provisioned 100GB virtual machine, then it will only consume 50GB of storage in your NFS datastore for the VMDK.

Please note there are other files that make up a virtual machine, not just the vmdk. You should be able to use datastore explorer in vCenter to browse your NFS datastore to see exactly what files have been created and the size of each file.

If these is space still unaccounted for, check your NetApp snapshots / snap reserve to see if NetApp is storing additional space for your snapshots.

> df -r                      ---- will also provide you reserved capacity on a netapp volume.

With the -r option, df displays the amount of space that has been reserved for overwrites. This is the amount of space set aside in the volume to ensure overwrites to reserved files succeed, multiplied by the value of the fractional_reserve volume option. If there are no snapshots and no block sharing (e.g. deduplication) it is not necessary to set aside space for overwrites and the value displayed will be 0. The reserved space is already counted in the used space, so the -r option can be used to see what portion of the used space represents space reserved for future use. This value will appear in parentheses if the volume is a flexible volume and its storage is not guaranteed; in this case no physical storage has been reserved and the reservation is effectively disabled.