EqualLogic has announced a new drive array and version 3.0 of its PS (Peer Storage) array firmware, which enables multiple pools of storage in a single iSCSI SAN.

The new PS400E array can have 10TB of storage with 750GB Seagate serial ATA (SATA) drives. These drives use perpendicular recording to achieve their capacity level. It is accessed over Ethernet using the iSCSI protocol.

The different EqualLogic arrays can be combined - mixed and matched - in a Storage Stack (rack unit) with their capacity combined into a single virtual pool of IP SAN (storage area network) storage.

With the firmware release a pool can be configured with capacity/performance characteristics to serve particular business and/or application needs.

It could have, for example, Raid 5, 10 or 50 protection characteristics. A SAN pool can be sub-divided into microSANs and these assigned to servers running particular applications, or belonging to particular business areas or office locations.

Data and disk volumes can be moved online between microSAN pools without stopping application access to data.

This approach parallels that of HDS and Sun in offering SAN virtualisation and layered management features using an intelligent front-end controller to drive arrays.

EMC and IBM do it differently by using in-fabric intelligence running on or through SAN fabric directors. All these vendors offer their virtualisation facilities on Fibre Channel SANs.

Individual Fibre Channel SANs from Cisco can be combined into virtual or VSANs.

Both Cisco and McData SANs can be aggregated together by IP routing to combine them into one logical SAN while isolating faults in an individual SAN to that SAN only.

IP SANs don't suffer from the Fibre Channel traffic surge problem making this necessary.

Other IP SAN vendors such as Intransa and LeftHand Networks don't offer IP SAN sub-division. The EqualLogic approach means that business units using microSANs can be charged for the SAN resources they use in a very visible way.

It also makes the SAN structure easily changeable as business needs alter.

EqualLogic and VMware are working together so that when a Sysadmn provisions virtual servers with VMware the servers can be assigned storage resources by setting up appropriate microSANs as needed.

Existing EqualLogic customers will be able to upgrade firmware, and all current EqualLogic PS series arrays can join in the microSAN party.