EMC CLARiiON AX100SC review

EMC’s traditional stomping ground in the network storage market has always been at the enterprise level, but the past year has seen it turn its not-so-inconsiderable gaze on small-to-medium businesses. Its NetWin platforms offer Windows-powered NAS solutions to the SME, while the entry-level CLARiiON AX100SC on test here brings fibre-channel SANs to the masses, with a range of features not often seen at this price.

The appliance supports two direct-attached servers or a switched SAN deployment for up to eight systems. The SC model on review comes with a single processor, a dual-port 2Gb/sec FC controller card plus a separate RAID cache card with 256MB of memory and a pair of battery backup packs. The standard AX100 is a different beast, as it provides dual processors, dual hot-swap power supplies, an extra 2Gb/sec FC controller and implements mirrored cache memory. It’s possible to upgrade the SC model but only by replacing the complete assembly, which slots in from the rear and mates with the hard disk backplane. However, all components are designed to be field-replaceable by users.

Installation is a little more fiddly than for a standard NAS appliance, although EMC’s claims that it can be accomplished in only 30 minutes are quite achievable. The Navisphere initialisation utility runs a discovery routine and asks you to apply a fixed IP address to the management Ethernet port and create an administrative user. Next, you run the Navisphere Server tool on each system that will connect to the AX100SC storage resources, as they need to be registered with the appliance. There’s more, as EMC’s PowerPath manages the I/O paths between the server and appliance and offers load balancing and failover.

General management access is via the Navisphere Express browser interface, which is highly intuitive. Any FC HBA connections are automatically detected and the registered server shown for each one. For storage, disk pools are created first and only RAID5 arrays are on offer. Available space is then split up into disk pools and assigned to your servers. New drives can be easily incorporated into disk pools and hot spares are also supported. Backup options are good, as the appliance uses virtual disk snapshots that can be assigned to another server with a tape drive attached.

The AX100SC scores well for performance, delivering good results during testing. After an introduction to our resident 2Gb/sec FC SAN built from a QLogic SAN Connectivity Kit, we direct-attached a Windows Server 2003 system to one port via a QLA2310 FC HBA. Running the open-source Iometer configured with two disk workers, 64KB transfer requests and 100 per cent sequential reads, we saw the server return an impressive 186MB/sec average transfer rate – not far off wire-speed performance for 2Gb/sec FC. Adding another Server 2003 system assigned to a second 20GB virtual disk in the same pool returned a cumulative 226MB/sec, although this will depend on the disk layout as we had only three drives to play with.

While performance for multiple servers clearly isn’t up with the higher-end FC products, it’s certainly a lot faster than iSCSI and NAS appliances. More importantly, the AX100SC successfully turns its back on the traditional high price of FC SANs and delivers a high-capacity product at a price the SME can afford.