Last time I blogged about SSDs the focus was on performance and capacity. Both characteristics are absolutely vital to the attractiveness of SSDs in enterprise class disk arrays. No doubt SSDs are all about performance, but capacity can’t be ignored either. We’ve seen nice strides in SSD capacity with introductions from Intel, Seagate and STEC. Performance also continues to rise now that we are over the initial seismic improvement as compared to our beloved but hopelessly slow hard disks.
All good work on the incremental evolutionary front.
[Angry reader: “INCREMENTAL! WHAT DO YOU MEAN INCREMENTAL? I THOUGHT YOU SAID SSDs WERE AN EVOLUTIONARY LEAP?]
[Calm and detached analyst: “that was way back in 2008, that’s ancient history. remember we live in internet time…]
In September 2008 I commented:
“…take the Humanoids running around an ancient continent. They made slow and deliberate progress using that opposable thumb to hit each other with sticks (remember the opening scene from 2001: A Space Odyssey?), and then one day there’s an evolutionary leap, and we have fire. Bam. New era …..”
Time to make an evolutionary leap: Dump the hard disk form factor.
The gene’s (no pun intended) are in place, and indeed some vendors have explored new possibilities. There’s Fusion-IO with their PCIe based storage adapter, TMS with their similar products and SUN pushing a memory stick form factor as well as their own PCIe adapter.
Why make SSDs look like a hard disk drive anyway?
Well for one, there’s a lot of legacy hardware designs in the world. From servers to mini laptops, physical space, connector and power has long ago been allocated for the hard disk. Likewise, in a midrange or enterprise disk array, disk enclosures are where you put storage devices, right? Isn’t that how the storage chromosomes get built? And don’t we need that to bridge from the high capacity hard disk to the high performance SSD?
Well, yes, at least for a little while.
But consider: If designers removed all the encapsulating hardware and protocols that surround legacy hard drives, disk array systems would get much simpler and cheaper. BAM. I see a new, yet evolved storage system emerging. A system using FLASH memory with no definitive form - and more interestingly - hidden inside the body of a disk array.
Losing the hard disk drive form factor sheds the mechanics necessary for mounting a disk, the wasted space around the mounting hardware, connectors, power supplies, fans, …you get the picture.
With all that extraneous hardware gone, just lay the FLASH chips down on a motherboard with or near the disk array controllers inside a common enclosure.
Image integrating FLASH memory into the controller design of a enterprise capable disk array. Resident with the controller hardware and connected onto the back side bus of the controllers via PCIe (or InfiniBand). Forget using SAS or fibre channel to the FLASH memory; part of the game is to drive down latency and that’s where PCIe or infiniBand can help.
NetApp and BlueArc have taken a stab at this approach by partnering with TMS, but the FLASH SSD’s enclosures are not fully integrated into the disk array frame. NetApp also offers a FLASH based cache card which gets close to the concept I’m promoting but lacks disk heuristics.
IBM get’s closer with its inclusion of SSDs (derived from the quicksilver demonstration product) in its SVC storage virtualization appliance. And Fusion-IO products keep showing up as add in adapters for enterprise servers.
So vendors are making progress but customers need an evolutionary leap from disk array vendors to get them to the next level. That next leap in the evolutionary tree promises higher performance, simplified operation and lower costs. All desirable traits in any species of disk array.
When that day arrives, FLASH memory loses the solid state “disk” tag and just becomes solid state “memory”.
posted by Gene Ruth