I have a problem with Kostadis’ latest posts on virtualisation and especially the ability of using NetApp V-Series as a virtualisation controller to reclaim unused disk and improve efficiency etc. The problem with the V-Series going into an existing environment, is that of the triumvirate of SVC, USP-V and V-Series virtualisation appliances/controllers is that it is just about the most disruptive thing that you can do.
SVC and USP-V will go in with no data migration and you can simply use them to virtualise your existing physical LUNs; that is the beauty of keeping things relatively simple and not relying on an additional abstraction layer such as WAFL. You can then migrate into the native SVC and USP-V formats at your leisure if you wish but you are not forced into making changes which potentially lock you in to the virtualisation vendor.
This is extremely important in today’s environment; firstly it minimises the amount of swing space that you require to do the conversion into a virtualised environment, secondly it minimises the amount of potential outage and thirdly it’s not a one way trip.
If all I want to do is reclaim unused disk and I am prepared to take the level of disruption that putting a V-Series into my environment; I suspect I might be better spending the money on analysing my existing environment and coming up with a better, more efficient lay-out and working at doing things better in my current environment.
For example, I would consider looking at Virtual Provisioning in my EMC environment; sure the licenses cost but it’s not going to be as expensive as going to a V-Series. I could convert from BCVs to Clones or Snaps. There’s a multitude of things which could be done before going virtualised. And once you’ve got your environment fixed, then take up NetApp and their space guarantee; don’t make things easy for them!
Don’t fix with new technology that which could be fixed by being a little smarter with your existing technology. You should always ask the question when being sold something new, can I do that already? It is amazing how often the answer is yes!
WAFL is a great technology with some great features but putting it in as a virtualisation technology would be an expensive mistake at the moment. Put NetApp in because you want to use NetApp but don’t put it in to virtualise your existing environment unless you are prepared for a whole lot of work. Take it from me, I’ve looked at it.
If you simply want to virtualise and build a consolidated pool of disk, you might well be better looking at SVC or USP-V. If you are looking at re-engineering your environment, NetApp is one of many companies you should look at but you know that anyway.