3.011: hot air reclamation

As I said in a prior post, sometimes we in the storage industry misbehave.

And other times, we spew fish stories – the kind that would make Pinocchio’s nose grow a couple of feet instantly.

The latest fish tale to be exaggerated beyond all sense of reality is the Unused Space Reclamation geyser, and to hear it told is to be convinced that the world of underutilized storage hath been all but eliminated at long last by the ingenuity and design of a unique new magic trick that allows host software to tell storage systems they are no longer in need of certain blocks within a LUN.

Now, don’t get me wrong – this feature is extremely valuable and it will undoubtedly help us all to improve storage utilization and efficiency. But I’ve seen practically every vendor who is shipping support for this feature today practically claiming to have invented it, that it’s a key differentiating feature for their platforms, and that THEY are the ones driving the hypervisor, host operating system, file system, database and volume manager vendors to implement this new feature.

Reality Check Time

Folks, the fact is that the T10 SBC-3 committee has stabilized the RFCs for the two (yes 2) new SCSI commands that underpin all this hoopla. With stable RFCs, vendors are now able to implement one or both of these new operations without concern that the API is going to change (again). And these standards have been under development for over a year, with representation and comment from practically every vendor in the list I scribed above – as with most standards, it has been a communal effort.

Somehow, the early adopters see no need to explain these facts to their audiences, allowing encouraging them instead to think that each vendor alone has mastered alchemy to turn deleted files into reusable space.

Alchemy, indeed…