NetApp can clone LUNs, either using FlexClones (in which case the FlexVol and the LUNs within that FlexVol are cloned) or using LUN clones (in which case the LUN is cloned within the same FlexVol). You’ll then need to deal with VMFS resignaturing, but the process is otherwise very similar. NFS is not a pre-requisite for using FlexClones.

BTW, do a site search for ‘FlexClone’ and you’ll turn up a number of articles, including a comparison of FlexClones vs. LUN clones.

Hope this helps!

I was under the impressoin that the Netapp must use NFS for flexcloning so it can manipulate the files on the NFS filesystem.

Or can Netapp read VMFS filesystems?

Or does it not need to and by some magic flexcloning works with both iSCSI/VMFS and NAS/NFS?

Cheers

This article was initially written from a block storage perspective, i.e., using LUNs, but you are absolutely correct–if we were using NFS, we’d run into the limit of 32 NAS datastores per ESX server.

Good point!

Why would you hit the limit of 256 LUNs? If its flexclone/netapp, surely its running on NFS, not iSCSI/VMFS .. in which case you would hit the NAS datastore limit of 32…?

Cheers
Alex

I’m looking forward to future cloning enhancements!

Yes Flexclones are considered equal to a typical volume. Anything you can do with a non-cloned volume can be done with a Flexclone. when you create a Flexclone from a snapshot, you’re actually creating a brand new volume that happens to share some blocks in the snapshot with the “parent” (original) volume. Writes to the Flexclone get allocated new space. Reads can come from the snapshot or from newly written blocks. Overtime, as the number of common(shared) blocks between the “parent” volume and the flexclone diverge, you have the option to split the flexclone from the snapshot at which point the “shared” blocks get copied out of the snapshot and into the space of the flexclone.

You can do the same thing with LUNs and the lun clone command.

There are more cloning enchancements on the way that server virtualization users will find extremely usefull not only from a povisioning but also from a recovery standpoint.

Thanks for the response! I appreciate your time.

So the key to understanding FlexShare in this instance (when it applies to FlexClones for provisioning VMs) is that all volumes are considered equal, FlexClone or not. I did not know that a FlexClone would be considered the equivalent of a volume; with that information, it makes a lot of sense.

FlexShare, A-SIS, FlexClones, Snapshots–all these technologies make NetApp a really compelling storage solution for VMware environments.

Thanks again for taking the time to comment!

Given that FlexShare is not tied to a specific protocol and applies on a per volume basis regardless of the type of the volume (Flexclone or not) and its contents (regular files or LUNs), there’s no protocol preference because it operates in the same manner in all cases.

In a multiprotocol array the ability to provide the peacful co-existence or various workloads regadless of the protocol is important. Afterall, you probably don’t want a volume with home dirs to have the same execution priority as a mission critical app. in an array appoaching full resource utilization.

In fact, I would equate FlexShare to VMware’s Resource Management where you can cap CPU and Memory resouces on a per VM basis. Now, if you take Flexshare and Multistore (which provides the ability to partition a physical filer into several virtual filers), what you end up with is capabilities similar to what ESX server is providing but for the storage side.

An area where Flexshare can be beneficial with Flexclone is Test/Dev. after you clone the primary volume, the clone resides on the same aggregate. So you may want to lower the execution priority of the flexclone in relation to the other volumes using the same disk resources.

Another area Flexclone can be beneficial is a case where one decides to split the Flexclone from the snapshot and create a fully autonomous volume. When that happens blocks are copied in the background from the snapshot into the Flexclone’s active space. Depending on the number of disks and back-end loops, this process can be quite intense (north of 350-400 MBps internal reads/writes). So you may want use Flexshare to limit the intensity of the back-ground copy.

happy holidays to you and your readers.

Just curious–how would you envision FlexShare being beneficial in an environment where we are provisioning VMs using FlexClones? We can consider using FlexClones with LUNs (FCP or iSCSI) or using FlexClones with NFS.

Hi, so with ONTAP 7.2 we offer FlexShare (no license required - priority command) where you can set execution priority for each volume relative to other volumes as well relative to system resources (i.e SnapMirror, SnapVault).