Storage Virtualization is sort of a game changer. The more I think about Storage Virtualization and the advantages it brings in storage environments with adding flexibility with migrations, efficiency, automation, management and importantly adds features that your existing storage arrays that might natively not be supported.
Storage Virtualization will take any storage device that is physically connected to it and remap the physical disks to xLUNs. These xLUNs can now take advantage of all the native features of the Storage Virtualization Array (Engine). Features could include creating Storage Groups, Various Raid Types, Site-to-Site Replication, Pooling of disks, Thin Provisioning, Synchronous Copy, Asynchronous Copy, Local Copy, Stripping, Snapshots, VAAI and Automated Storage Tiering. Again doesn’t matter if your existing Storage natively does not support these features.
Two features that every customer wishes they had right now….VAAI and Policy based Automated Tiering (including Sub-LUN Tiering)
Who Supports Storage Virtualization
There are several manufacturers that support Storage Virtualization today. Some of the leading storage virtualization arrays/engines include IBM SVC, EMC VPLEX, HP SVSP, HP P9500, Hitachi USPV/ VSP.
Same can be said about VAAI (vStorage API for Array Integration), an amazing interface that VMware provides for its technology partners to offload rather intense storage related functions natively within storage devices, compared to the old approach where VMware Host did these tasks. This means Storage Processors need to be able to pick up these massive xcopy, lock operations and block zeroing.
Many storage vendors have already provided VAAI support while many have it on their roadmap and have planned release over the next few months. EMC Clariion was supported Day 1, 3Par similarly supports it with 2.3.1 MU2 InForm OS, while HDS supported VAAI on the AMS platform Day 1.
Automated Storage Tiering
Automated Storage Tiering is another great feature to have natively within storage arrays, but not every vendor supports it today.
Not all the data you have, need to be on the fastest tier, but as your application writes data, it can write to the fastest tier and then demote if the data is not being used. Similarly if there is any data that is frequently used, based on the policy can be moved up to a higher tier. So in short if you keep a good balance of SSD’s and SATA drives, you should be able to keep all your applications happy, all your users happy, all your DBA’s happy and importantly meet your SLA’s.
So initially the idea was to offer this at a LUN level. Create policy, if the LUN is busy based on the time of the day or the month of the year, move it to a faster tier. But then followed the concept of Sub-LUN Tiering. Well not the entire LUN needs to be moved, only a certain set of blocks, chunks, pages are hot and they need to be promoted to a faster tier. Helps tremendously reduce your operations on arrays and keeps cache free.
Compellent is considered a market leader in Automated Storage Tiering and were the first ones to take it to the market. Followed by HDS, EMC and 3Par. Not all storage vendors offer LUN tiering and Sub-LUN tiering with its storage platforms today.
Where am I going?
Well, for a second, lets think…..
The storage environment that you might have today, does not support all the needed features your applications and your business may require. Example VAAI and Automated Storage Tiering including Sub-LUN Tiering.
Why not push the physical Storage assets behind these Virtualization arrays / engines and start taking advantages of the native features offered within them including VAAI and Automated Storage Tiering including Sub-LUN Tiering.
If you are anxiously waiting for features from your existing storage vendors, which may be on their roadmap or may have been promised but never delivered, you do have a choice to closely look at Storage Virtualization and take advantages of these features without a major overhaul in your storage environment.