Enhance Technology UltraStor RS16 IP-4 review

Enhance Technology specialises in affordable IP SAN solutions for SMBs, and its latest, the UltraStor RS16 IP-4, makes bold performance claims. We were supplied with a diskless appliance, but the price above is for the device with 16 1TB Enterprise SATA II drives installed; a full house of 2TB drives will set you back £7,274.

However much storage you go for, the appliance has four independent iSCSI Gigabit data ports, and redundancy comes in the shape of a pair of 460W hotplug supplies and hotplug fan modules. For expansion, the controller’s SAS port supports up to four RS16 JS 16-bay disk shelves and up to 80 drives.

Dual controllers aren’t supported, and the single SAS expansion port means redundant links can’t be created across expansion arrays. The controller is also lacking a battery backup pack, so we recommend using a UPS.

RAID options include stripes, mirrors, RAID5 and dual-redundant RAID6. The latter two can be striped in RAID50 and 60 configurations, and then there’s N-way mirroring, where instead of two drives, the array can contain multiple mirrors for N-1 failover.

Installation is swift. The tidy web interface’s quick-start option can suggest an optimal RAID array based on the drives installed. For testing, we used four 1TB WD SATA drives, took manual control and created a RAID5 array.

Up to eight arrays are supported, and each one is called a volume group (VG). Within these you create user data volumes (UDVs) that are your iSCSI virtual drives, and each VG can contain multiple UDVs of varying capacities.

For access control, each UDV can be assigned to specific iSCSI host initiators, or a wildcard entry makes them available to all hosts, and you can specify read or read/write access. The controller advertises a single iSCSI node name with all accessible virtual volumes appearing below this as LUNs. This isn’t a major issue, but as CHAP authentication is applied at the node level this will apply to all hosts and LUNs.

Snapshots of UDVs can be run manually, or at scheduled intervals, and used for rollback purposes. They can also be presented as new read-only targets, although make sure they’re attached to specific hosts only; we found using wildcard access can cause them to appear as uninitialised drives.

You can migrate VGs to different RAID array types, and expand their capacity into extra physical drives. UDVs can also be expanded into spare space within their parent VG simply by clicking on a button in their size column and entering a new capacity.

For performance testing, we created four UDVs and assigned each one to a different test server. These were all running Windows Server 2008 R2 and were also logged into a dedicated portal IP address on the appliance.

With one server running Iometer, we saw read and write speeds of 112MB/sec and 110MB/sec. With a second server, overall throughput rose to 223MB/sec and 220MB/sec. With all four servers in the mix we recorded cumulative raw read and write throughputs of 446MB/sec and 421MB/sec, showing no contention for resources.

The Enhance Technology UltraStor RS16 IP-4 delivers top IP SAN speeds under load and looks good value. SMBs that don’t want the added expense of dual RAID controllers should definitely take a closer look.