News

posted on 08 April 2008 13:37

Magnitude storage array supplier Xiotech has announced its new high-end Emprise storage disk array based on sealed Datapacs containing multiple disk drives, offering direct-attached and SAN storage that virtually eliminates downtime and scales from 1 terabyte to 1 petabyte in capacity.

The product offers innovations in its fundamental building block, failure detection and prevention, and also performance. The basic component is a sealed Intelligent Storage Element or ISE containing 20 or more disk drives.

There are two models. The Emprise 5000 is a 3U high, direct-attach (DAS) or Fibre Channel switch-attached system, comprising just one ISE, forming a complete, self-enclosed and virtualised storage system. By varying the drive choice the ISE can be configured for performance, capacity or a balance between the two.

The Emprise 7000 can have up to 64 ISEs, meaning an upper capacity limit of 64 x 16TB = 1024TB. Both models have full Magnitude array capabilities: web services-based ICON management facility; storage virtualisation; a distributed cluster architecture; intelligent (thin) provisioning; and a data replication suite.

Xiotech CTO Steve Sicola said: "It's time for a new foundation for storage. Exponential growth in data storage capacity continues, but reliability, performance and manageability haven't kept pace. We have fundamentally rethought storage from the ground up, and with the ISE have developed break-through technology, which is tested, proven and ready to go."

ISE

A DataPac has one or two ISEs using technology Xiotech bought from Seagate. An ISE has dual active-active Managed Reliability Controllers which bring RAID, cacheing and drive management and diagnostic intelligence much closer to the disk drives.

There are 2.2TB, 4.8TB, and 16TB ISE configurations and only Seagate 3.5-inch and 2.5-inch disk drives are used. Solid state drives (SSD) are a future possibility.

Compared to standard drive arrays the ISEs offer improved drive vibration control and cooling. The controllers are battery-backed for a 96 hour period and also have mirrored write-back cache.

Each ISE presents its capacity as a RAID-protected virtual pool. The ISEs are available in high-performance (2.2TB), balanced (4.8TB) and high-capacity (16TB) configurations.

Start-up Atrato also uses sealed canisters of disk drives in its Velocity1000 array.

Self-healing

The drives are monitored and errors diagnosed with a fix-in-situ approach. Each ISE contains a spare drive ready to use. Most drive failures, Xiotech says, can be recovered from and drives are, in effect, remanufactured in place if an error is detected. This takes place with no interruption in service. Recovery is granular and only one drive surface may need to be recovered.

In a 15 month trial Xiotech monitored 208 ISEs containing 5,900 drives, and didn't record a single drive service event (one needing a technician to replace a failed drive or a failed ISE.) The company says an ISE is more than 100 times more reliable than a standard drive array enclosure. However Xiotech does not offer a four, five or six nines reliability rating.

Pillar Data has issued a 5 'nines' rating for its new Axiom 500MC high-end array product.

Performance

In SPC benchmarks an Emprise 5000 offered the lowest cost IOPS in the SPC-1 benchmark (5,892.6 IOPS @ $3.53/IOPS), and the lowest cost per SPC-2 MB/sec measure (645.60 MB/sec @ $32.25 each). It is not the highest performer in absolute terms.

The average SPC-1 IOPS cost is $14.12. The average SPC-2 MBps cost of 25 other systems tested was $175.28.

Concept

The concept behind Emprise is that disk arrays are scaling to include ever-greater numbers of disk drives. This brings a consequernt increase in the drive failure rate. RAID rebuild times are getting longer yet many failed drives are actually found to be valid when returned to the manufacturer.

By making the array building block a sealed set of drives with much more intelligent controllers able to better diagnose and recover from drive errors, the Emprise offers far higher reliability than standard arrays but not at greater expense.
 
User View

Rick Young, network systems manager at Texas A&M University College of Veterinary Medicine & Biomedical Sciences, said: "The Emprise 5000 system is providing us with very impressive throughput and greater reliability than I thought possible. With the new system I no longer have to deal with failed disks. Rather, the ISE takes care of everything, so it will automatically fire up, move data if needed, do a repair, and move the data back, without ever going offline. Plus, we can add ISEs and/or upgrade to Emprise 7000 to meet additional storage demands. It's really impressive."

Price

The SPC-1 Emprise 5000 configuration with 146GB drives costs $20,820.

^{[Chris Mellor.]}