Avere bets filers are crying out for more tiers

Four storage levels starting with NVRAM

FTX speeds and feeds

The FTX hardware comes as a 2U rack-mount box containing 64GB of DRAM, 1GB of NVRAM, and either 1.2TB of internal SAS drives (FTX 2300) or 3.6TB of internal SAS (FTX 2500 model). The FTX2300 can scale to 29.2TB per cluster and the FTX 2500 up to 90TB per cluster. There is a maximum of 1.6TB of DRAM per cluster.

There is no flash storage tier, though; that comes in the next product release. Both FTX models run Avere O/S v 1.0 which has its general availability scheduled for October 15. THere are redundant network ports, power supplies and cooling.

NFS v3 (TCP/UDP) and CIFS are supported as client protocols with NFS v3 being used to access the back-end SATA NAS storage.

Single FTX performance is said to be 80,000 read ops/sec, 49,000 SPECsfs97 ops/sec, and 23,000 SPECsfs08 ops/sec, with aggregate throughput being 1GB/sec read and 325MB/sec write.

Avere provides a management GUI, with policy-based management features, SNMP support and email alerts.

There can be up to 25 FTX nodes in a cluster, with N+1 failover. FTX tiers are shared globally within a cluster. Customers can buy more FTX nodes as they need to scale performance, with Avere claiming that performance grows linearly as nodes are added.

FTX performance and alternative approaches

Bianchini says an FTX-front-ended filer or filers needs far fewer spindles to sustain a performance level. Avere calculated the requirements sing various manufacturers' products to achieve 100K SpecFS97 operations. Compared to an FTX-system Avere says you would need 13 times more disk drives and a 5.1 times increase in cost.

A NetApp alternative would mean 10.7 times as many drives and a 5.2X cost increment, BlueArc would entail 10.5 times as many spindles and a 2.8X cost increment while a Panasas-based system would need 9.4 times as many drives and a fourfild cost increment.

With FTX use, Avere says there are comcommitent reductions in power draw and data centre floor space needs, and in cost per I/O, compared to these other suppliers.

Boabchini offers Avere's views of other ways of scaling filer performance. A filer supplier may rely on over-provisioning fast drives and short-stroking them, which needs more electricity data centre floor space. There is also a level of management oveerhead involved in scaling systems. The use of Gear6-like caching appliances applies only to read work loads and is non-persistent, and typically restricted to just the NFS protocol.

A filer controller cache, like NetApp's PAM, has an inability to scale separately from the controller and it is proprietary. (We note though that you can scale PAM within the controller by adding more cards.) Bianchini says of Texas Memory Systems (SamSan) and Fusion-io solid state storage apperoaches that there is no tier zero management and there is a high media cost.

The F5/Acopia switch has an inability to scale outside switch and it is not transparent. Bianchini would say that Avere's FTX technology scales filer performance with none of these disdadvantages or restrictions.

The net of this

It's a coincidence that Dataram is coming out with its XcelaSAN flash-based caching front-end layered onto SAN storage arrays at roughly the same time as Avere has its front-end FTX layered onto filer arrays. Both aim to plug into existing environments and both aim to accelerate, respectively, block and file-based I/O from the storage arrays they serve, but Avere uses more techniques to do so.

Avere's technology is innovative and its avoidance of including bulk NAS storage in its product means that customers do not have to rip-and-replace their existing filers with Avere ones. Instead they can front-end the filers with an FTX node or two or more to accelerate filer read and write I/O performance and so support more filer-accessing multi-core and virtualised servers from their filer estate.

Indeed, if Bianchini is right, they can do so from a consolidated filer estate because all filer disk drive over-provisioning and short-stroking can be jettisoned in favour of simple basic SATA filer arrays with all I/O acceleration carried out by an FTX layer. Similarly filer use of flash drives as a tier zero in font of hard disk drives, or filer controller flash caches, can both be junked in favour of the single FTX accelerator which does its magic on all front-ended filers, being, in that respect, open.

List pricing of the FTX appliances starts at $52,500. Actual benchmark data hasn't been published yet but, with Avere's use of SPEC file operation benchmarks we can be moderately confident of Avere benchmark data being published fairly soon though.

Steve Duplessie, the founder of storage consultancy ESG, is quoted in the Avere release: "Conceptually, an architecture like this could quite literally change everything we thought we knew about storage and I/O. If the Avere architecture can perform as intended, it might just turn decades of thinking on its head." ®

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