You are correct–deduplication and FlexClones do not address IOPS requirements, only storage requirements. You should still size the SAN to handle the IOPS requirements with the appropriate number of spindles, storage controllers, target ports, etc., etc. Deduplication isn’t just about active vs. inactive data, though; it’s about duplicate data. Data may be active, but if it’s the same data as exists elsewhere (looking at this from a block level, not just a file level), then why are we storing multiple instances of it?

Hope this helps!

I’m no SAN expert, just Jack-of-all-trades-VMware guy, but de-dupe or flex-clones have absolutely nothing to do with handling more or less IOPS, right? They seem to have everything to do with decreasing the amount of disk space necessary. When designing a SAN solution to accommodate a customer’s VMware storage needs, the first thing I do is look at IOPS and make sure my SAN solution has enough spindles to provide the required IO for the VMs. Secondary in my calculations is total disk space needed. So, I’m guessing then that the only place de-dupe actually pays for itself, is in cases where you have larger volumes of inactive data than active data. Would that be a correct assumption? If so, then NetApp vs an Equallogic SAN: I would purchase the same about of disks, it’s just that with NetApp I could get away with cheaper 146 GB disks instead of 300 GB disks. But in an environment with lots of active data, and lower percentage of inactive data, there would seem to be no benefit to de-dupe.

As always, thanks for your work! I’m just trying to get my head around when NetApp is THE solution for a customer, and when Equallogic/Compellent or random other SAN is good enough.

Sean Clark

Good questions! NetApp deduplication is post-process, meaning its deduplicated after the fact. That’s one of the reasons I pointed out for using FlexClones, in that you don’t need to wait for the deduplication process to get the space back. If total space is a concern, then FlexClones may be a better option even with the added complexity.

Deduplication and FlexClones both really shine in VDI environments, because the scale of the environment makes the impact of these technologies that much more powerful.

As for the legendary YouTube video….here are my thoughts:

http://blog.scottlowe.org/2008/02/28/i-love-it-but-its-not-available/

Last time I checked, this functionality wasn’t available in Data ONTAP yet (although it may be included in the very recently released ONTAP 7.3). So I can’t really say what that’s going to look like. Keep in mind, though, that without integration in VirtualCenter it will suffer from many of the same problems as FlexClones.

Thanks for reading!

Nice article. I always enjoy reading your thoughts on NetApp and VMware technologies!

My take on FlexClone and A-SIS is a little different. I think of them as being used for complimentary but distinct purposes.

FlexClone is fantastic for DR testing in a VMware environment. Most Storage technologies make you break replication relationships to read/write the destination volume which is required by VMware datastores to bring up VMs. With FlexClone, the administrator can just FlexClone the SnapMirror destination FlexVol and connect the new read/write capable datastore into VMware. This can be over FCP, iSCSI or NFS of course. The FlexClone FlexVol takes a second to create, and can initially take up 0 space…beautiful.

A-SIS Deduplication is awesome at efficiently saving the admin a ton of space, not only on the source/production datastore volumes, but also on SnapMirror replicated destination volumes (at DR for example). I have personally seen an 80% saving on NetApp NFS datastores running a mix of Windows XP and 2003 VMs.

Together these two technologies work great.

1. A-SIS De-duplicate your production Flexvols holding VMs = Large Space Savings!
2. Replicate your entire VMware production environment with SnapMirror to DR (Only de-duplicated data gets sent, saving on time, bandwidth, and storage needs)
3. Use FlexClone to create instantaneous read/write clones of your VM Datastores at DR. No need to break your replication relationship during DR testing!
4. Use DR ESX Farm & VI Client to connect up to FlexClone datastore and test DR Strategy
5. Use VMware’s new SRM (Site Recovery Manager) which does integrate with NetApp FlexClone and SnapMirror to offer “push button” DR testing and failover features. (Hopefully they add NFS support in the next release)

I too wish there was some integration of these tools in the VI Client. VI Plugins do exist, and I use the SVmotion Plugin a good deal already. http://sourceforge.net/projects/vip-svmotion/

Both NetApp and VMware have strong Software Development Kits, which help make an opportunity to add NetApp technologies into VMware’s VI Client. Citrix has done some of this already with their NetApp Adapter for XenServer, which automates some basic storage provisioning and A-SIS features within their GUI.

Dave

All the stuff you say - screams out VDI to me… And from what I have seen from VMware - its likely the storage vendors will have an edge over VMware for sometime..

Lastly, the now legendary NetApp YouTube demo - where they create 100 VMs for real via SnapClone. Is that for real. I’ve heard some people say it takes hours to do that - not minutes… What’s your experience been?