EMC has introduced a new CLARiiON, the AX4, which replaces the entry-level AX0-150 with up to five times more disk drives. It's cheaper than Dell's EqualLogic arrays, terabyte for terabyte.


The AX4 is an iSCSI storage area network (SAN) array product. It can have 60 disk drives, meaning 60TB capacity when 1TB drives are delivered in March. There are only 750GB drives available for now. It can also have faster SAS drives, the first EMC box to do so, enabling a two-tier array with SAS tier 1 storage and SATA tier 2.

The AX4 supports iSCSI, and Fibre Channel connectivity as well.

The CLARiiON AX4 is built on the same architecture as that in the larger CLARiiON CX3 mid-range storage array. This offers "Five 9s" availability - 99.999 percent of uptime. It features a mirrored cache design, built-in standby power supply, continuous disk consistency checking, active-active controllers and hot swappable components which provide better levels of data availability and reliability.


The software and controller enables the AX4 to connect to up to 64 hosts at the same time. These can be Windows, Linux, Unix, NetWare and VMware Infrastructure hosts. The AX-150 supported just 10. Clearly the AX4 is much better suited for life as a virtual server-attached array where one physical server could run 10 virtual servers.

Built-in features enable real-time volume expansion, through MetaLUNs, making the allocation of storage for new virtual machines simple and seamless. The CLARiiON AX4 includes EMC's Virtual LUN technology, which can be used in conjunction with VMware Storage VMotion for the non-disruptive migration of multiple virtual machine disk files.

In addition, the AX4 supports replication software: MirrorView, SAN Copy, RepliStor, and Replication Manager to provide high uptime levels in VMware environments.

AX4 SAN capacity can be configured with just a few mouse clicks by following simple, graphical interface instructions and installation wizards. System management is intuitive and simplified by using the latest version of EMC Navisphere Express, which has a graphical approach to creating and managing disk pools and virtual disks. It means storage capacity can be created, allocated and re-allocated in seconds, whilst an application remains online.


The intended market for AX4 is that of SMB customers and VMware environments. That's where the iSCSI support is crucial as the AX4 can slot right into existing Ethernet environments without needing investment in complex-to-operate Fibre Channel (FC) fabrics. Existing FC customers can, naturally, use it too.

The AX4 can be deployed, expanded and reconfigured in a VMware Infrastructure environment; indeed, it would be surprising if it could not. EMC says it can also be deployed, expanded and reconfigured in traditional (non-virtual server) IT environments too, in both cases with no application downtime.

Charles King, A principal analyst at Pund-IT,said iSCSI is becoming very popular in small/medium business (SMB) environments. This is: "especially important in VMware environments where new virtual servers require consolidated storage. EMC's CLARiiON AX4 is ideal for SMB's virtualised environments since it includes key features that make it easy for businesses with few or no dedicated IT resources to set-up, manage and allocate networked storage."

Price and availability

The AX4 is available now from EMC and from EMC's channel, including Dell and NEC. We might see some change in EqualLogic pricing. On the other hand we might see EqualLogic products being migrated up market and out of the SMB space. But there has to be a fit with the AX4 line in some way and not a glaring overlap with uncorrelated pricing.

A 3TB AX4 can be bought for $8,599 (£4,300 at ordinary conversion rates). That's $2,866/TB, A 2TB Dell EqualLogic array would cost $22,500, meaning $11,250/TB which almost four times more expensive. We wonder whether this aggressive EMC pricing sent Dell elsewhere, hunting for margin and buying EqualLogic.

Dell's version of the AX4 starts at $13,858 (c£7,000) for 3TB ($4,610/TB) suggesting that the starting, not to say startling, EMC starter price may be unrealistic though.

Dell's PowerVault MD3000i, announced in September last year with up to 45TB capacity and starting at a 1.1TB minimum for $5,649 which is $5,135/TB - more expensive per terabyte than the Dell AX4. This is heading towards being twice as expensive per terabyte as the EMC-supplied AX4 at starting price levels.

Techworld speculated that, at that time, Dell couldn't afford to wait for EMC to deliver a product in this space. Now that it has, the MD3000i could be revealed to be a stop-gap array in Dell's storage product line up.

Dot Hill has just announced an extended OEM deal with HP that could lead to new SMB products from HP. Its All-in-One line is perhaps being readied for a re-vamp.

HDS has its recent SMB system, the SMS-100, and both IBM and NetApp have SMB storage product lines. Storage resellers are going to get a lot of phone calls from suppliers, and small/medium businesses are going to get a lot of calls from storage resellers looking to complement their VMware implementations.

EMC will be hoping that the AX4 can pre-empt a lot of those calls by combining VMware server virtualisation with AX4 purchases.