ADMIN: Highly available storage virtualization

Virtualized vs. Software-Defined

Software-defined storage (SDS) technology goes one step further. For example, on each physical server involved, hardware-independent software responsible for storage virtualization is installed, which acts as a hypervisor, bundling and centrally orchestrating the storage resources of the servers. In the case of VMware with vSAN or Windows 2016 with Storage Space, such functions are already included in the operating system, which allows the storage resources of the individual servers to be completely decoupled from the hardware and grouped into pools. Services such as deduplication, compression, and data protection are also offered.

A kind of erasure coding (i.e., the intelligent storage of data on several instances) ensures that the data is stored in a fail-safe manner. Compared with conventional SAN storage virtualization, this also means that the local or directly connected hard drives of the individual servers can be managed. SDS solutions can even integrate the unused RAM of the servers as a kind of cache with extremely fast access times. SDS as a relatively new virtualization technology is generally considered to have the greatest potential for the future. However, it remains to be seen to what extent this technology can also be used for highly heterogeneous server environments or I/O-intensive applications.

REF: http://www.admin-magazine.com/Articles/Highly-available-storage-virtualization