Don't you have experience when you research on “Software-Defined Storage” you find actually there are pretty huge difference between each SDS products. In fact the term of SDS is bit blurry and every vendors has it's own definition. It could be appliances, storage management software or distributed scale out storage.
It's easy for us tell what IZUMO defined the term SDS but in this blog post I would like to expose this fantastic technology from larger scope of view. For this purpose I find SDS mapping graph created by Mr. Makuta from Techno Systems Research is very useful. I've got permission to quote it here so I'll use this mapping to describe many different types of SDS.
In above mapping it categories SDS into five categories which are Control, Virtualization, SBS (Software Based Storage), Software the function of external storage and Hyper Converged and also divided by whether it's delivered as Software (at left) or Hardware (at right).
Let me pick up some of characteristic products on each categories. ViPR from EMC which is categorised as Control-SW can not only manage EMC products but it can handle NetApp, HP, Hitachi storages as well. So ViPR is not a product that creates storage system by its own but it can control many difference machines and make virtual storage pool or execute similar operation from single ViPR management console.
Software the function of external storage example is Virtual VNX. Virtual VNX can provide EMC VNXe as a software which is an entry model of EMC VNX series.
In common, at the moment, when we talk about SDS most likely they are Control-SW, SBS and Hyper Converged. Control-SW is a software for managing storages as I pointed out before so there's a big difference from SBS and Hyper Converged. Many SBS and Hyper Converged products are distributed storage system. Usually SDS claims that strength of SDS is its High Availability and Scalability. And those are features of distributed storage.
Benefit of hardware based storage is it's easy to predict actual performance of the machine because they are fully tested by its hardware provider. But at the same time you'll be locked in to those machines for at least few years.
On the other hand SBS-SW will work on any hardware with different machine, different spec and different capacity. You're free to use and combine any kind of IA server. That gives you very flexible system structure and good cost performance. Those are new technology trying to escape from legacy storage systems.
On next blog post I'll be focusing on SBS-SW which includes our SDS product IzumoFS.