Tag Archives: SDS

The SDS (Software Defined Storage) era started 20 years ago

Many customers are asking this question of where does storage sit in the “Software Defined” market place of today.

I gave this some thought a while ago and when I see the current buzz of doing everything “Software Defined” I can draw no other conclusion than storage is at least 10 (if not 20 or 30) years ahead of the entire market.

The virtualisation and abstraction of storage in the sense of “Where does my data go?” has been done many many years ago by first abstracting the physical disks and put these behind a physical controller (CU), then the CU got virtualized and has been running in software for many years. On the open systems side RAID has abstracted the physical device to provide an protection and virtual address layer where hosts could logically store their data. Pooling of different kinds of storage whether homo- of heterogeneous has been done a fair while back.
From a Fibre Channel network side the use of zoning and VSAN’s became a standard more than 10 years ago and if the market (ie you Mr Customer) would have demanded it an OpenFlow kind of architecture in the storage world would have been created 15 years back.

So when comparing this today to virtual network switching or virtual machined and hypervisor architectures I’d say we’ve (as in the storage industry) done this a long time ago.

The flexibility of moving network switches and virtual machines to other data-centres is more difficult to achieve with storage. Not for the storage itself, you can spin up volumes from everywhere in the world, but more for the data. Virtual host and networks are ephemeral entities which can stop and resume tasks at leisure at different locations. Locality has never been an issue for a virtual host, copy the memory structures to a hypervisor on a different location and resume operations over there. Addressing and data transfer is just re-routed on the go. The same you now see with virtual network switches. A logical entity is created which can accept and forward packets to a given destination without having to keep track of what happens to it as soon as they have processed it.

Storage is a whole different ballgame since there is a nasty little thing called “YOUR DATA” which you don’t want to see tagged as ephemeral. Networks transfer pieces of information from A to B and then forget about it. Similar with hosts and applications, they obtain information from your business, process that information and then store it. As of that moment these entities can forget about the data and as soon as they are started on another location they expect the same data to be obtainable from the last know location where they stored it. If either location is unavailable or the expected data is invalid, corrupted or unusable in any sense you’ll see that no upper layer network, host and application has any use, no matter how “Software Defined” they are.

The name of the game is still: It is YOUR data and your business depends on it. The storage industry started “Software Defined” a long time ago and only the server and network people start to catch up. Don’t be fooled by letting anyone tell you otherwise.