Storage devices, especially today’s ubiquitous hard drives, will evolve but we don’t need to look further. The future of hard drive arrays will be flash hybrids featuring non-volatile memory bolted externally or fitted internally. These hybrids will out-muscle all-flash arrays by providing server flash cache integration and better data management.
Fundamentally, the aim of improving storage devices is to get more revs out of the engines making applications run faster, allowing more virtual devices to be mounted, and pushing processors executing codes instead of waiting for the storage array to feed data. Hybrid flash can make the entire computing process speedier because it can recall information faster than a spinning disc.
That the hard drive usually causes IO bottleneck is a known fact for many array vendors. The popularity of multi-socket servers with multi-core Central Processing Units means that more data are needed from any storage device.
In a busy IO-bound environment, CPUs usually have to wait for longer period of time as it runs out of thread for longer than is desired. Most of the time, the issue starts from slow transfer of data from hard drives even if there’s a good OS kernel scheduling work for a processor, assuming the data isn’t already in the RAM cache.
A favored technique to make faster data transfer from and to hard drives is to add spindles to boost array response. However, according to experts this tactic is now over. The main concern now is where to put the flash: in all-flash arrays, in disc drive arrays, or in servers, or even in all three places at once.
Today, traditional disc drive array makers are being confronted on three fronts: firstly, all-flash array (AFA) vendors are driving prices down as they increasingly offer faster IO rates as the cost-per-gigabyte of flash approaches disc price tag levels. Secondly, there are now new mutant flash-with-disc arrays that offer more or less the same near-AFA speed and hard drive array capacity. Thirdly, hardware accelerators like Avere offer inexpensive flash-based caching devices that sit in front of the disc array, right in the middle of the data path, thereby accelerating data requests.
These attacks on three fronts force disc drive array vendors at a great disadvantage in terms of performance and they have no choice but to adapt a NetApp and turn their drives into hybrids as well. This means complementing, for example, a flash cache to the controller, or adding flash as a volume-level cache inside the array. If vendors will not do this, customers can hybridize their products by simply adding internal flash accelerators in front of the disc drive storage arrays.
In any way, hard disc drives as we know today will most likely transform into a more robust and faster storage devices, thanks to the efficient flash technology.