Wednesday, April 24, 2013

VAAI for Dummies - AKA VAAI for Me! - Part IV - Release The Clones!

Hi Everyone,

Today we're going to talk about Fast File Clone or also known as Native Snapshot Support.  This technology is near and dear to my heart since it's a VDI technology!  So Remember how I wrote that article a little while back about how VDI Cloning Can Cost You More Then You Think!?  If you haven't read it, I highly recommend it. :-)  This piece of VAAI technology helps eliminate the extra I/O the storage array needs to perform when using hypervisor snapshots because the snapshot process is now offloaded to the storage array.

So how does this work?  Along with the plugin in ESXi 5.1 you need VMware View Composer 5.2 and you get VMware View Composer Array Integration, or VCAI.  When clones are created both a flat-file and checkpoint file are created.  Instead of a snapshot, like traditional Linked Clones, a NetApp FlexClone is taken of the gold image.  During a refresh operation, the checkpoint file is re-cloned from the storage array so no snapshots are created on the ESXi server.  This also eliminates any 512 byte partial I/O if VMFSsparse is used instead of the new SEsparse.

So create some clones and take a look at the /vmfs/volumes directory.  You'll see there's a flat file that's the size of the original machine and might think, "Hey!  I'm losing all of my space savings using this technology instead of Linked Clones."  Ah, very perceptive my friends, but remember this is an NFS technology and these are thin provisioned clones which point back to the gold image, so only the changes actually take up any space!

NetApp has had the ability to create VDI FlexClones for some time now, but with VCAI, you don't have to use two separate tools anymore.  In the past, clones had to be created with VSC in vCenter and although you could import automatically if you wanted, you still could not do this functionality from View directly.  Now, from within View, choose to create Automated Linked Clones and once you hit Advanced Storage Options, select "Other Options" and "Use native NFS snapshots (VAAI)" and that's it!  Need to Refresh/Recompose, go ahead, it's all integrated now.

NetApp is currently working on certifying the technology and hopefully it will be certified soon!  When I hear the good news I'll be sure to pass it along.

Until Next Time Friends!


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