Most legacy storage systems consist of a storage device that has three basic parts: the shelves that hold the storage, the CPUs that provide the array with storage services and the network interfaces that allow the storage system to be accessed by the connecting hosts.
Recently, software defined storage solutions have emerged that abstract the storage services from those CPUs, capabilities like LUN management, RAID as well as snapshots and replication. Software defined storage (SDS) allows these storage services to run on almost any physical hardware, including as a virtual appliance within a virtual infrastructure. SDS also allows for multiple vendors’ storage systems to be managed from the same storage solution, essentially freeing the organization from being locked into a particular storage hardware vendor.
Hyper Converged Storage – Software Defined Storage’s Next Step
For the most part software defined storage solutions have a dedicated set of controllers, a redundant pair, typically attached to dedicated storage arrays. Hyper converged storage (HCS) takes SDS to the next level by leveraging virtual host CPU horsepower to run the SDS software enabling it to scale-out across the virtual hosts, creating a storage controller architecture freed from the legacy dedicated control model. In a similar fashion HCS leverages the internal storage capacity of the servers and aggregates that capacity into a shared storage pool.
Taking Software Defined Storage Further
The next step in the development of SDS is to continue to better leverage the resources available to it in the hyper-converged model. As we discussed in the recent article “Three Ways To Improve Software Defined Storage” the first of these is RAM. Almost every virtual host in an architecture has some RAM capacity available to it. If a portion of that memory can be used to improve data efficiency then both network and storage capacity efficiency can improve.
After this excess RAM has been allocated for data efficiency services, any remaining capacity could be aggregated into a high speed storage tier. The next generation SDS could then use this as part of a three tier storage strategy (RAM, Flash and HDD) to provide the highest performance infrastructure at the lowest possible cost.
Software defined storage has the ability to manage multiple vendors’ storage hardware from a single software platform. Hyper converged storage represents an evolution of SDS to make it more tightly integrated with the compute and network layers. The logical next step in the development of SDS is to continue to better leverage the compute resources available to it, like RAM and server side flash, to improve performance and data efficiency.