EMC yesterday announced a slew of news about its flash product lines. The biggest news is that the all-solid-state XtremIO scale-out array is moving from beta test to a controlled introduction, where customers can actually order it. EMC also announced it's expanding its range of PCIe SSDs, now called XtremSF. The company is also re-branding its server-side caching software from VFcache to XtremSW.
I've written about XtremIO before, most recently here. XtremeIO's scale-out Fibre Channel architecture fits EMC's customers well. The future of storage is definitely scale out, and established storage vendors will have to develop, or acquire, purpose-built, all-solid-state systems like XtremIO to compete.
Much of EMC's presentation centered on server-side flash. The company announced four new PCIe SSDs with capacities from 550 Gbytes to 2.2 Tbytes. The new SSDs all have x8 host interfaces, while some competitors use just four lanes. I, for one, am in awe of a multiterabyte SSD, even if EMC's 2.2 Tbytes don't challenge the 11-Tbyte behemoth Violin Memory announced this week.
In a break from EMC's past practices, the company will sell the PCIe SSDs alone for use as direct-attached storage or with other applications. In another break from EMC's past practices, it presented some benchmark data comparing the new XtremeSF cards to Fusion-io cards (thinly veiled as "Brand F").
While EMC didn't announce a new version of the artist formerly known as VFcache (now XtremSW), it did talk about a roadmap that includes coherent cache support via replication for clustered application like Oracle RAC, mirrored HA server-side caching and pooling. This is much like Virident's FlashMAX Connect.
The fact that EMC's new PCIe SSDs use eMLC flash, rather than the more expensive SLC, proves that the SLC era in the data center, short as it was, is coming to an end. When EMC first started shipping SSDs for its arrays, it went to great lengths to describe them not as SSDs but as EFDs (enterprise flash drives) that used the good stuff (SLC flash) and were an entirely different animal than the pedestrian MLC SSDs you'd put in a server.
Over the years, flash controller technology has advanced to the point where even hardcore enterprise applications can run on eMLC, and even MLC, flash-based devices provide the three- to five-year lifetimes customers require. Secondarily, the market has also been educated to the realities of write endurance exhaustion, so users aren't demanding SSDs that last forever.
Missing from these announcements was any mention of EMC's "Project Thunder," which was to provide a very low-latency, shared flash environment that would link multiple servers via Infiniband to a box full of PCIe SSDs. I was never a fan of the whole Thunder idea because a group of servers could instead use server-side cache management software and a LUN from an all-flash array like XtremIO. Sure, it would have 1 to 5 microseconds of additional latency, but I could also use the shared flash array for other things, rather than buying a special-purpose box.
As EMC rolled out Thunder to beta users, the company discovered that users either wanted the extremely low latency of local PCIe flash, or data management features such as snapshots and replication that an array provides. Thunder was neither fish nor fowl, and is now sleeping with the fishes (alongside Luca Brasi).
