Texas Memory Systems gets some enterprise street cred
High availability flash array here at last
Texas Memory Systems (TMS) is getting some enterprise cred – by introducing a high-availability, shared-access RamSan flash array.
Competitors such as Violin Memory have criticised TMS RamSan flash SAN arrays for not having high-availability (HA) features that enterprises require when running business-critical applications.
The RamSan-720 comes in 6TB and 12TB versions, using single level cell (SLC) flash in a 1U enclosure, and delivers up to 400,000 random read IOPS (4K blocks) and has up to 5GB/sec sequential bandwidth with less than 100µs latency. There are four host connectivity ports which can run 8Gbit/s Fibre Channel or quad data rate InfiniBand.
Concerning latency and wattage, TMS says it has lowered latency by keeping all data flow operations in hardware and only using embedded CPUs for book-keeping operations. It uses low-power embedded PowerPC, which need only 2 watts each. These two features help it to build the RamSAn-720 in a 1U enclosure.
It requires 300-400 watts to run and TMS says it's the highest availability SAN flash array, the highest-performing one, the highest-reliability one, and has the highest SLC flash density, with no single point of failure. How is the HA implemented?
High availability features
First of all there are redundant hardware components; two Series-7 flash controllers per board, on both the primary and expansion boards, and two or four per module. The gateway interface has dual ports to the backplane. There are redundant management controllers, interfaces, cross-bar switches, data busses, power supplies, clock circuits and batteries.
Next there are two RAID controllers per system with dual external interfaces. RAID 5 is implemented within flash modules (9 data and 1 parity) and across flash modules (10 data + 1 parity + 1 active spare), which protects against a flash module failure. TMS calls this 2-Dimensional Flash RAID. The cross-module RAID is new to TMS.
Each flash chip has its own ECC (Error Checking and Correction) and TMS provides a variable stripe RAID inside the system as well. These two items along with the 2D RAID provides four layers of data protection and correction.
A TMS spokesperson described the HA features:
Previous RamSan products were very reliable with redundancies covering nearly all failure cases, but we recommend application-level high availability software for true high availability, or mirroring those systems to provide true high availability at the hardware level. The 720 boasts all these reliability features plus more to form a system with hardware-based high availability in the box.
Positioning and competition
TMS has said it aims to continue expanding its product range by expanding into storage management, building smaller systems and more powerful systems.
We asked TMS to position the RamSan-720 and -710. The general idea is that the 710, limited to 5TB of capacity and with no fewer HA features, can be used for small apps and the 720 for multiple apps and/or larger ones.
Is there any comparison with power needs for competing systems, such as the Huawei Symantec OceanSpace, Dorado 2100, Kaminario K2 Flash, and Violin Memory 3000 and 6000 arrays? TMS said: "The closest competitors to the 720 are the Violin SLC arrays, where both systems require three to four times the power and physical space of the Texas Memory Systems product—but get less performance due to architectural design."
Concerning the Violin systems: "The RamSan-720 provides similar capacity yet better performance than Violin but at 1/3 of the power, in 1/3 of the rack size and at 1/3 of the complexity. Just compare the datasheets."
We asked about price, TMS said: "Street price: £13,500/TB. This means that the Flash price per TB in the RamSan-710 and RamSan-720 is the same, and competitive with Tier 0 disk storage. The overhead is also the same price; in other words there is no extra charge for the HA."
The RamSan-720 will be available at the end of January. ®
I think it was a bad architecture that bought down the Australian airline,
Cool, but I think they are about two years too late. It's crazy that an "enterprise" level storage vendor didn't have a SPOF solution before this. Well, at least with this they won't have to worry about bringing down any more Australian airlines.
I too, like the look of this beastie
I first had my attention drawn to TMS when they were advertising 1,000,000 IOPS for their RAM SAN (that has now been clipped, probably by the marketing mavens or more truth in advertising).
Sho' enough ..... at these prices flash array may soon become a credible altenative to traditional FC, SATA or SAS disk arrays. So please do rock on... Our heavily discounted FC 4 G/B SAN disks still cost us about 1200 £ a TB a couple of years back. But performance? As usual, it depends on how you crunch the numbers. FC can provide a sustained data burst of up to 700,000 IOPS on something like the DS5000 but I'm not too sure how that raw measurement comparably applies to a flash array. The flash vendors may be using average (or constant) rates over a sustained test to come up with a more realistic figure which takes everything into account (like no platters or disk heads). I still haven't seen a decent and honest race comparison between any of these SSD offerings and current "gold-standard" Fiber Channel products.
For those who could only afford SAS or SATA disk arrays, however, the new SSD products will pound them into the proverbial performance dust (which is why SATA and SAS are nearly always used for comparison, methinks). But then the price differential yawns all the more hugely.
The real sex appeal of a flash SAN array comes from its lower power consumption, faster access, and higher reliability (not to mention the reduced space requirements). But is all that worth paying at least 10x the price of today's high end storage products per TB? Maybe, wait and see.....
If a flash array SAN (I think we will soon need a new acronym here, how about a FASAN?) can do what our big-pig, dually-redundant monolithic FC disk structure does today, better and faster (and more affordably? ...oops) we probably wouldn't buy any new FC storage. But that is still a big IF right now. We won't because we must first amortize an initial large investment. SANs have a comforting tendency (for the buyer at least) to stay in production for a long time ( > 5 years). Our last storage array served reliably for nearly 10 years. Hardware prices tend to become much lower when working within such extended time frames. However, for the budding or established cloud vendor who needs to replace a creaky storage infrastructure, now may almost be the time to go flash (depending on their applications and budget, obviously).
Anyway it is all VERY exciting to watch. But I am glad our shop doesn't need to decide now.