Dot Hill AssuredSAN 3420C review

Prices for 10-Gigabit Ethernet (10GbE) products have fallen enough that the technology is becoming affordable for SMBs. Storage supremo Dot Hill has taken advantage: its AssuredSAN iSCSI appliances specifically target SMBs looking for a high-speed, high-capacity network storage solution that won’t break the bank.

The 3420C in this review has 24 SFF hot-swap drive bays, and comes equipped with Dot Hill’s brand new controller that sports a pair of 10GbE SFPs ports. The 3430C model supports twelve LFF hard disks and you can choose from SAS, SATA and SSDs.

The price above is for the single-controller model, but if you want full fault tolerance a dual-controller version starts from £7,876. If 10GbE isn’t your cup of tea you have plenty of other controller choices: Dot Hill offers versions with quad 8Gbits/sec FC, eight Gigabit iSCSI or eight 6Gbits/sec SAS, plus a combo version with two 8Gbits/sec FC and two Gigabit iSCSI ports.

Fault tolerance is excellent, as the dual controllers run in active/active mode where their cache contents are mirrored across a high speed, low latency interconnect. Dot Hill’s EcoStor does away with battery backup packs; the 2GB cache in each controller is protected by a combination of capacitor and flash memory.

The chassis has dual redundant power supplies, but if there’s a complete power failure the cache contents are written to flash memory. When power is restored, the contents are written back to the cache and the capacitor takes far less time to recharge than a battery.

Expansion potential is equally impressive. All controllers have separate 6Gbits/sec SAS ports for daisy-chaining up to seven JBOD units with fault tolerant paths. You can mix 12-bay LFF and 24-bay SFF expansion chassis, and the only other limit is support for a maximum of 96 LFF or 144 SFF drives.

Installation is a swift affair. We pointed a web browser at the primary controller’s default IP address, where we were greeted by the smart RAIDar management interface. If you need to change the IP address first, you can connect a PC to the controller’s mini-USB port and use the CLI.

A wizard makes light work of controller configuration, then you can move on to storage provisioning. A wizard is also provided for this, but with manual control selected you can create virtual disks (vdisks), choose a RAID array type, add hot-spares and opt to have the vdisk split into equal sized volumes.