The end of storage virtualisation?

Is "classical" storage virtualisation still relevant?

We’ve never seen a day quite like yesterday. Coinciding with VMWare’s annual conference, a slew of announcements landed in the SearchStorage ANZ inbox, as vendor after vendor piled in to announce their latest tools to manage storage in a virtualised world.

NetApp, HDS, IBM and others all let us know about their new software and how it will make the chore of managing storage easier in your VMWare environment.

We draw a few conclusions from the deluge.

One is that The Law of Unintended Consequences is one of the most powerful forces in the known universe. Virtualisation, after all, is supposed to make IT management simpler. But user after user complains that virtualisation actually creates all manner of complication. Yesterday’s raft of announcement confirms that server virtualisation is not all plain sailing, at least where storage is concerned.

Another conclusion is that conversations about storage virtualisation are few and far between at the moment. We suspect this is because storage virtualisation is not as immediately powerful as server virtualisation. It is also, surely, because the storage industry used virtualisation-style techniques long before the word “virtualisation” became fashionable. RAID, after all, is a pretty basic form of virtualisation, as it sees multiple physical drives treated as a logical volume. Thin Provisioning, last year’s hot button, also has virtualisation as its essence. Other storage techniques also consider logical volumes.

It’s also worth asking just how applicable storage virtualisation is to large users, most of whom necessarily deploy heterogeneous storage devices to provide the different levels of service required by different tiers of storage. Each of these devices will have its own virtualisation-style hacks built in to make them addressable as logical units. The benefits of then applying further virtualisation to combine different arrays as logical devices are not always readily apparent.

Another perspective worth considering is the Storage Networking Industry Association’s definition of storage virtualisation, a twofold affair that starts with the familiar description of logical abstraction but adds a second strand that defines the technique as:

“The application of virtualization to storage services or devices for the purpose of aggregating, hiding complexity or adding new capabilities to lower level storage resources.”

The services strand is interesting because at least one vendor we know of – HDS – is keener on virtualising services than it is virtualising devices. The company’s Vice President and Chief Technology Officer Hubert Yoshida explained to SearchStorage ANZ in July how the company can take the management services built into its devices and use them to manage other storage devices from other vendors.

This approach, we understand, does away with the unctuous situation of having multiple management consoles for heterogeneous devices and also helps users stay out of the clutches of enterprise management framework vendors and their projects-without-end.

We now wonder if this "classical" approach to storage virtualisation, together with the slew of new management tools for storage operating under VMWare, might not make logical storage virtualisation seem a bit irrelevant.

It certainly seems to be today, even if we only use the deluge of VMWare-related products as a gauge.

Simon Sharwood travelled to Japan as a guest of HDS.

Read more on SAN, NAS, solid state, RAID