iQStor iQ2850 iSCSI Storage System in Storage appliances

IP SANs may be an affordable option for network storage in SMBs but you still have to watch out for hidden costs. Many vendors consider features such as mirroring and snapshots as options and will charge a premium for them. iQStor is new to the UK market but it offers these features and more as standard in its iQ2850 appliance.

The price of the review system includes support for unlimited managed snapshots and volume copies along with standard support for MPIO fault tolerance. There are extras but these are aimed more at enterprises and include synchronous and asynchronous remote replication, database agents and iQStor's SAN Manager software.

This well-built 3U chassis has room for up to 15 hot-swap SATA drives and the review system includes ten 1TB hard disks. iQStor also offers FC variants of this chassis but these hard disks are expensive and are losing out to SAS drives. The price includes one RAID controller but you can go for two where they function in active/active mode. RAID options are good as along with stripes, mirrors and RAID5, the controllers support dual-drive redundant RAID6.

Expansion potential is excellent as each controller has a pair of 4Gb/sec FC ports which accept iQStor's J2880 SBOD expansion units. Up to 15 can be daisy-chained from dual controllers allowing capacity to be increased to 240TB. You can also mix FC and SATA SBOD units in the same daisy-chain.

Installation is simple as you point a browser at the controller's IP address to load the System Manager interface, which opens with a graphical rundown on the condition of the hardware. If you want full manual control you start by creating RAID arrays where you select an array type and pick the drives to be included. Pools come next and these can comprise one or more RAID arrays. VDisks are your iSCSI virtual volumes and you decide on their size, the pool membership and the assigned data port.

CHAP authentication is permanently enabled and profiles allow multiple schemes to be created where each contains a username and a CHAP secret. All hosts can be allowed to access selected VDisks or you can assign them to specific hosts using LUN mapping. You'll need to set up host aliases first and we found it annoying the dialog box wasn't wide enough so we couldn't see the whole IQN for each server.

Along with array membership, you can designate drive bays as global hot spares which make them available to all arrays in the event of a failure and array rebuilds will happen automatically. If there's enough spare space in the pool, VDisks can be expanded by entering a new value for capacity in GB. Snapshots provide point-in-time copies of VDisks and are created by selecting a source and a pool for the snapshot to be stored in.

The same procedures apply for creating local VDisk mirrors as well. This can prove useful for testing as once a mirror has been created you split it so the copy becomes a new VDisk that can be made available to your test systems. In the event of a problem a volume can also be restored from a snapshot.

The System Manager offers some management tools that are activated with a licence. Policies are used to monitor the capacities of VDisks and once a threshold has been breached the appliance will increase them by the selected percentage. You can use policies to monitor an attached UPS and close the system down before its battery runs out and also control the number of spare disks that must be kept ready for use.

To test MPIO we created a single VDisk, assigned it to both ports on the controller and then logged in from a host server initiator using both IP addresses as targets. We had no problems creating a fault-tolerant link and during a copy of a 2.5GB video clip to an iSCSI target we disconnected one network cable from the server and watched it continue.