Believe what you want about solid-state storage's ultimate destiny in the enterprise. For the moment, at least, it provides an extremely efficient and effective server cache, which can now be integrated into legacy storage environments more closely than ever.
EMC this week unveiled the new VFCache server Flash caching system, the result of the long-awaited "Project Lightning" designed to establish Flash-based server cache as a new storage tier. As a PCIe-based solution, the platform takes direct aim at Fusion-io and other rivals who view PCIe/solid-state infrastructure as an alternative to expensive SAN and NAS installations.
VFCache is a means for EMC to engage users who want simplified storage infrastructure but are not yet ready to dispose of the SAN just yet. The system works with the VMAX, VNX and VNXe storage platforms as a means to improve performance for mission-critical applications by tripling throughput and cutting latency in half.
In essence, the system builds a fourth tier of Flash-based storage and then sub-divides that into multiple mini tiers corresponding to the number of servers in the array, says the UK Register's Chris Mellor. In order to boost I/O, VFCache adds source and destination metadata to VNX's automated tiering tool, allowing it to better determine the level of storage a given data block should receive. It also enables faster data off-load to lower tiers should a server fail and the cache is lost.
The need for more innovative cache solutions is driving solid-state development on a number of levels. Last month, OCZ Technology purchased Sanrad, a developer of virtualization and Flash cache systems. The company plans to integrate the company's VXL platform into its solid-state drive portfolio to improve cache performance in highly virtualized environments. VXL is compatible with vSPhere, Hyper-V and Xen virtual environments and supports most operating systems like Windows, Solaris and Linux.
Server-based storage tiering will do wonders to alleviate the bottlenecks that automated tiering can produce, according to Storage Switzerland's George Crump. All that shuttling of data from tier-to-tier can hamper overall storage performance, even when 10 GbE or 16 G Fibre Channel infrastructure is present. Server-based tiering allows the most active data to reside only a PCIe link away from the server, so not only can it be accessed and delivered much more quickly, but overall stress on the SAN is lowered by reducing I/O spikes and balancing loads more effectively across storage resources.
It would seem, then, that we have only begun to scratch the surface when it comes to Flash-based storage tiering. It probably won't be long before everyone from Dell to HP has a server-tiering solution in the channel, if only to make their established SAN and NAS platforms more relevant in an increasingly solid-state-centric data center.