But it all depends on how you define it because I have seen definitions which basically are 'Abstracting the physical disk away from the logical disk' i.e any device which hides the physical spindles from the server that it is attached to can be considered Storage Virtualisation. This means that any NAS head, any Disk Array etc can be considered to be virtualisation…in fact, anything which moves away from DAS is virtualising your storage.
Personally, putting a USP-V to consolidate less than 100 Terabytes of storage would be IMO madness. Now, I'm sure there are people who have done it but you would be better to put in an AMS, a Clariion, a NetApp, a IBM DS4K, a 3Par Inserv, an EVA…almost anything than a USP-V. That strikes me like putting a 747 on the London->Paris route; you could do it and it'd get you there but you'd be nuts! A smaller plane or even a train might be a better idea.
Of course, you might be charging SMEs so much for their spinning rust that it does become cost-effective to put a virtualisation device in but that's a subject for another blog!!!
Yes! “Storage Virtualization” can be just about anything! That means all of us vendors get to claim ours as “the best form of it.” (Of course, some of us are more right than others.) Reminds one of the ambiguity associated with “cloud”, but maybe the right word for storage virtualization is “fog” – as in something that obscures the differentiation of storage products.
You mention the USP V, but the USP VM is surprisingly inexpensive (once discounted). In fact, in our case USP VM would have been less expensive than NetApp or EMC CX. Less than EMC because our old CX700 would have been replaced with their proposal. Less than NetApp because of migration costs associated with re-using the CX700 as backend v-series disk.
Alas, we ended up going NetApp. Love it.
Question Ryan, how would have you got your existing CX700 into the USP VM? Would that not have been a migration exercise in itself?
And as for NetApp, if you’d gone v-Series; the software licensing is a killer…or did you go v-Series?
Actually, one thing where EMC do very well on the CX is the s/w and h/w maintenance…Their five year cost tends to be very good IME. Where-as both HDS and NetApp’s maintenance costs tend to be much higher. YMMV
As a consolidation, simplified management, and ROI tool, a virtualizer (in the sense of a layer that not only abstracts but provides heterogenous advanced functions – i.e. USP and SVC) you may not need hundreds of TB to get an advantage from such a device.
Remember people may still have 73GB or even 36GB disks that they want to keep, so it can be many controllers worth of disks. I guess you could say, if you have more than 2 or 3 controller devices, virtualization (in terms defined in my first or second blog post 2 years ago) can provide a benefit.
USP is a very expensive way to lock yourself into an HDS array to gain this function however!
I still wonder…firstly keeping those small disks under maintenance is getting increasingly expensive but actually increasingly hard. And then there is the ongoing running costs; I suspect that in very nearly every case that the cost-case is at best neutral for virtualising very small aging estates.
BTW, I agree with your definition of Storage Virtualisation…but I’m not sure everyone else does.