Dell is adding Micron-based Express Flash to its servers and will feed the server flash beast from Compellent arrays.
Brian Payne, executive director of PowerEdge marketing at Dell, showed us the 2.5-inch SSD slot at the front of one of Dell's twelfth generation servers at a launch event at the temple of UK rugby, Twickenham Stadium, and said it was a 300GB Micron SSD that would be slotted in.
As we now know, LSI CacheCade software will be used to turn the one to four SSDs into a cache by automatically sticking hot data blocks fetched from disk into the flash. LSI's WarpDrive SSD didn't make the cut though, Dell going with Micron, which is the primary supplier for EMC's server-located VFCache.
The point is to make Dell's servers chew through applications faster, and the company said two Express Flash drives provides up to 18 times more Microsoft SQL Server transactions per second, while CacheCade provides up to three times more transactions per second with 55 per cent faster response time on SQL. It can help support three times the number of Microsoft Exchange mailboxes and process twice as many messages. Avoiding disk and network latency with I/O requests is clearly a good thing.
Brad Anderson, Dell's enterprise solutions group president, said VFCache did not cache write data or provide high-availability (HA) for servers. Express Flash will obviously cache read blocks. How about write data? Anderson did not want to give too much help to the competition in understanding Dell's plans: "It will be full HA ... there is more to come but we're not going to say when," or what for that matter.
He mentioned RNA Networks in passing. This sparked off thoughts how RNA could virtualise memory in a group of servers and make it a single virtual resource for those servers. It leads on inevitably to the idea that RNA tech could potentially virtualise Express Flash in Dell's servers and share that between them, enabling HA.
Anderson confirmed that Compellent arrays would extend their automated data placement tiering and treat a server's Express Flash as the top tier in their scheme. Asked about Compellent arrays potentially having faster array-server interconnects than 8 Gbit/s Fibre Channel or 10GbitE he said: "We fully understand latencies and will have the most ubiquitous solution out there."
No clues there as to whether the Compellent arrays would get InfiniBand or some other fast server connect technology. They could feed Express Flash through existing interconnects with RNA technology providing the fast server-to-server access to the flash-held data.
Will EqualLogic arrays support Flash Express? "Given a sufficient time horizon I think all our storage will support it."
A theme coming out of Dell these enterprise-focused days is that Dell's server, network, storage and software products are "open, but work better together". The idea that all of Dell's storage product lines could help Dell's servers go faster by tiering data from their disks or solid state drives into the server flash and so cut IO latency exemplifies that nicely.
All server vendor's storage arrays are going to have to do this: Fujitsu, HP, IBM and others such as Hitachi Data Systems and Huawei and NEC. All storage array vendors are going to have to do this too: they can't afford for their products to be seen to be hobbling the coming generation of flash-enhanced server beasts. ®