Dell this week became the last of the major storage vendors to start selling an all-flash storage array, although...
its Compellent SC220 did beat a few well-hyped platforms to general availability (GA).
The Dell Compellent SC220 that is available as an all-flash or hybrid system was announced at Dell Enterprise Forum in June and became generally available this week. It beat EMC's XtremIO to GA, although XtremIO was formally announced last March and has been in beta for months. NetApp is also promising a FlashRay all-flash system in 2014. EMC and NetApp do have other all-flash arrays on the market -- the EMC VNX7600-F and NetApp EF540.
Dell takes a unique approach with its flash arrays. The Compellent flash system uses tiering software to place data on single-level cell or multi-level cell drives, with most writes going to the higher-performing SLC and reads to the less-expensive MLC.
Most storage vendors are getting away from expensive SLC and moving toward MLC. However, Bob Fine, director of product management for Dell storage, said the Compellent all-flash array costs around $5 to $10 per gigabyte, depending on the mix of SLC and MLC. "We can deliver all-flash that's comparable to a 15,000 rpm hard drive solution," he said.
Dell's flash-optimized SC220 is a 24-slot array that ships with six 400 GB SLC drives and six 1.6 TB MLC drives. Customers can fill the other slots with MLC flash, SLC flash or SAS spinning disk.
Compellent storage plays big role in cloud provider services
Houston-based cloud service provider iland Internet Solutions is using an all-flash version of the Compellent SC220 to store customer application data, according to Dante Orsini, iland's senior vice president of business development. Iland does not offer cloud bulk storage, but Orsini said his company's back-end storage plays a big role in providing services.
Orsini said the Compellent setup lets iland concentrate on providing performance around reads or writes, depending on the customers' requirements. He said he also likes that he can start with only flash and add hard drives later.
"As a cloud provider, we have a different view on storage," Orsini said. "Our customers' environments are dynamic. We have thousands of customers, some focused on performance characteristics, others more focused on scale. You have to look at what that does to a storage subsystem.
"A lot of these flash systems have been designed for the enterprise. They provide a lot more performance at the read level, and they're not too concerned about writes. For us, it's often the polar opposite. In a dynamic cloud, customers could be doing massive write operations."
Orsini said iland started with the 12 flash drives and will decide how to populate the other drives depending on performance needs.
He said iland's plan is to offer several tiers of service, including one using all flash and another "flash-assisted" tier that uses a combination of flash and hard disk drives.
"We're not seeing a lot of use cases yet for pure-play flash all of the time," Orsini said. "But we know we have to provide an ultra-high-end performance tier, and we have to be able to do it cost-effectively."
Orsini said iland also considered startup SolidFire's all-flash arrays. SolidFire sells exclusively to cloud providers. Orsini said the startup has "a great model and really has considered how to scale form a cloud perspective," but he felt the company is still too new to take a chance on.