How solid-state arrays are getting enterprise-ready

Storage giant EMC's space-saving upgrades to its XtremIO all-flash arrays reflect wider industry efforts to broaden the uses for the high-performing but costly storage tier.

The battle to be the world's number one supplier of all-flash storage arrays is hotting up, with EMC prioritising features that maximise the usable capacity of the costly but high-performance storage.

The market for all-flash arrays is set to be worth $3.5bn by 2017 according to analyst house Gartner, and EMC is hoping to build on strong sales of its XtremIO all-flash arrays, which have generated more than $100m revenue since being launched in November last year.

EMC is still a relatively new player in the solid state array market, which according to Gartner, was last year dominated by IBM, with its FlashSystem line, and flash specialist Pure Storage.

Yesterday saw EMC try to seize greater market share by revealing an upcoming software upgrade for new and existing XtremIO arrays aimed at extending their usable capacity.

Maximising available storage is important for flash-based arrays because the cost of solid-state drives per GB remains so high relative to hard disks.

Following the upgrade data stored in XtremIO systems will be compressed, as well as deduplicated. Compression and deduplication will happen inline, occurring at the time data is written to the drive. That data reduction on the fly is made easier by the speed at which data can be accessed on solid state media.

This compression and deduplication can boost the usable capacity of the XtremIO flash array to up to six times the raw storage, according to EMC. However, the amount of space freed up depends on the type of data stored, with dedupe achieving a greater reduction when applied to data associated with virtual desktop infrastructure than to data stored in databases. By contrast database footprints can be more effectively reduced using compression, so by offering both inline-deduplication and compression XtremIO arrays will be able to maximise capacity for a range of workloads.

Manufacturer of medical devices Boston Scientific has deployed eight XtremIO X-Bricks to run thousands of instances of workstations in a virtual desktop infrastructure, with inline-deduplication reducing the storage requirements to a point where it could fit on the array.

Another new feature enabled by the upgrade aimed at extending the capacity of raw flash storage is the addition of writeable snapshots.

This feature allows different users to work on multiple copies of the same data without creating separate copies of the data and metadata for each snapshot. The system only records the differences between each snapshot, greatly reducing the storage needed and ensuring similar IOPs for each version, as the core data is stored on the same volume.

EMC demoed the performance levels attainable using the writable snapshot system at an event in London yesterday, showing how latency stayed below 1ms when users were accessing multiple snapshots of a single virtual machine at a rate of 60,000 IOPs.

In tests, the software upgrades enabled OLTP databases to run nearly 1.5 times faster, two times better throughput for data warehouses and the time taken to clone virtual machines to be halved, EMC claims.

The software upgrade will also allows data to be encrypted at rest using 256-bit AES.

These features will become available at different times. The inline encryption and writeable snapshots are available today with XtremIO 2.4, while inline compression and other performance improvements will be enabled with XtremIO 3.0, which is expected to ship this quarter.

Joseph Unsworth, research VP at Gartner and flash storage specialist, said the upgrades helped EMC to keep XtremIO competitive.

"They plugged a few important holes. Compression was a big one. Writeable snapshots is also important. This will help them defend, or go on offensive, better against their competitors," he said.

But while there are already arrays offering a similar feature set, he said EMC's scale and its ability to service a large international organisation is a major asset.

"There are other arrays that are competitive in terms of feature set, as well as cost structure. Pure Storage already has compression and deduplication, another company SolidFire also has compression, scale-out and deduplication, for more for a cloud-oriented play. There's a whole list of other solid state array vendors in this space but the ones that truly are going to be able to challenge the likes of EMC are going to have to be able to bring not only that product and the data services, but also global sales and support."

But while EMC plans to increase the usable capacity of its all flash arrays, the cost of its drives still sit above some of its competitors.

"Ultimately we want to see EMC work on more aggressive cost structure of their drives. They're using very robust enterprise-grade drives, whereas some of their competitors are using notebook drives that are considerably cheaper," said Unsworth.

And EMC's competitors are also not standing still, NetApp will announce more details on a new flash array later this year and HP recently added in-line deduplication to its 3PAR 7450 array, which it claimed pushed the cost of usable storage down to below $2 per GB.

During the next year Unsworth anticipates the number one spot in the market will be contended by last year's number one IBM and Pure Storage, but said EMC is well-positioned with XtremIO.

EMC also announced changes to the size of XtremIO clusters yesterday, introducing a new entry-level XtremIO option called Starter X-Brick, a 5TB array, which can be expanded to a full 10TB X-Brick without disrupting availability.

As well as introducing a new entry-level XtremIO array, EMC increased the maximum scale-out cluster size to up to 120 TB, made of up to six 20 TB X-Bricks, with 12 active controllers, enabling a 50 percent IOPs performance increase and 50 percent more capacity, while maintaing sub-1ms latency.

EMC is also trying to pre-empt customer concerns about the durability of flash storage by offering a seven year guarantee for its XtremIO arrays, as well as a programme to fix the cost of its annual maintenance fee for seven years.

This quarter EMC will also add support for more its own and third party storage software on XtremIO. Support will be added for EMC ViPR SRM Suite, EMC ViPR software-defined storage platform, EMC VSPEX, EMC PowerPath, VCE Vblock, Vmware VAAI and Vmware vSphere plugins. XtremIO will also be supported as Cinder block storage in OpenStack clouds this quarter.