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October 30, 2009



Good article... I found the tidbits throughout the article on benefits of NFS storage for vSphere interesting. Definitely some good benefits.

Unfortunately...we're a Microsoft shop, so vSphere would be the ONLY thing we'd use NFS for. If it was a cheap license, we'd have it in a second...but when you're only going to use it for a small list of additional features (even if they are great), it makes the cost justification a little tough.

On the other hand -- we're running FC for storage and like this over IP for several reasons. Hopefully VMware and NetApp can continue to integrate further and some of the same benefits can come to FC VMFS datastores.

Good info...thx

Ian Forbes

Great articles. I learned a bunch. Thanks. I actually ran into a problem at a client recently related to VMFS and WAFL not being in sync with "actual" capacity metrics. Thin is thin only on day one. When vm's are destroyed or storage vmotioned to another datastore, the source datastore will reflect the new "available" space but WAFL will still report the "old" available space.
I didn't know the hole punching or space reclaimer feature has already been discussed for ESX vmfs datastores. In my post I mentioned how it would be nice to have space reclaimer for vmfs - run from the Virtual Storage Console :)
So, my question is when will space reclaimer be a reality? My second question is what is your suggestion in the meantime to have the "reclaimed" space in the vmfs datstore be reflected at the WAFL level?

Here is my post in Netapp Communities:


Ian Forbes

Just to clarify, I'm hoping to be able to run space reclaimer against a vmfs datastore, not the GOS. I thought that's what the demo from VMWorld 2009 was going to show - but it showed space reclaimer against a vmdk in a GOS (iSCSI LUN).

Paul Evans

Excellent posts, Vaughn. I was glad to find convergence of viewpoints around the fundamentals between your and Chad Sakac's posts. I learnt quite a lot from them and have summarized my learning at


Vaughn Stewart


Thanks for the follow up - great post


Paul, Vaughn

Do you know any method allowing reclaiming free space with thin provisioned VMs WITHOUT storage vmotion?

We have a structure in our NFS volumes and VMs are located in different subfolders rather then in root folder of the datastore. This is because we run scripts on regular intervals to take backups of VMs.

If we SVmotion VMs between datastores it will break our structure because SVmotion moves VM folders to root folder of the datastore.

Do you know any way to avoid it?

Vaughn Stewart

Re: [NetApp - The Virtual Storage Guy] invisible submitted a comment to VCE-101 Thin Provisioning Part 2 Going Beyond

@invisible thanks for the question. As a global technical partner of VMware NetApp designs its tools and applications to follow VMware designs including the storing of a VM in the root of the VM Homedir. I would suggest that the model you have deployed will inevitably cause you issues with products from VMware and their partners. You may want to reconsider some aspects of what is deployed.

As for storage reclamation in VMDKs... There is nothing available today which completes this process without migrating the data (ala Storage VMotion). Work is going on with the SNIA via T10 storage reclamation. This work will eventually show itself in all systems, including ones from VMware NetApp.

As more on this front becomes available I will post on it.

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