Within each RG you create multiple Virtual Disks (VDs) which are your iSCSI targets. These can be any size and if you run out of room you can load more drives, add them to the RG and extend selected VDs as required.
The appliance advertises one iSCSI node name with all accessible VDs appearing under this as LUNs. For access control CHAP authentication is applied at the node level but you can limit access further by assigning VDs to specific iSCSI host initiators or using a wild card entry for global access.
Snapshots can be run on selected VDs manually or at 15 minute, hourly, daily, weekly and monthly intervals. From both the web console and QCentral you can select a VD and view all associated snapshots.
To rollback a VD you just choose a snapshot and select this option from the drop-down operations menu. Snapshots can be exposed as a new read-only or read-write target and initiators assigned so they appear as a new drive.
Virtual disks can be quickly cloned and used for testing or local backup purposes
Cloning and replication
The cloning feature will come in handy for testing and for basic VD backup as it allows you to create complete replicas of source VDs. You start by creating a Backup VD that's the same size as the source VD.
When it's ready, just select the Set Clone option for the source VD, choose the Backup VD as the target and either run it manually or use the same scheduling options as provided for snapshots. It runs a full copy to the clone after which it uses snapshots to keep it up to date with the source VD.
VD replication over a LAN or WAN to another appliance is possible with the optional QReplica feature. The only drawback is the second Gigabit port on each controller on both appliances must be dedicated to this task.
Iometer recorded a high raw read throughput of 9Gbits/sec for a RAID-5 array comprising WD SAS hard disks
Performance testing
To test the appliance we created a range of VDs within a RAID-5 array and introduced the appliance to the lab's 10GbE network. For our host system we used a Broadberry CyberServe with dual 2.6GHz E5-2670 Xeons, 48GB of DDR3, an Emulex OCE11102-NM dual port 10GbE adapter and Windows Server 2012.
With jumbo frames enabled, we saw Iometer report fast raw read and write speeds for 64KB sequential transfers of 1157MB/sec and 1084MB/sec which equates to 9Gbits/sec and 8.5Gbits/sec.To test maximum IOPS we changed the Iometer block size to 4KB and saw a reading of 130,000 IOPS.
For general database performance testing, we used 256 outstanding I/Os, a 16KB block size, 66 per cent read, 34 per cent write and a 100 per cent random distribution. After leaving the test running for an hour Iometer settled at a respectable 9,700 IOPS.
Conclusion
Our performance tests with SAS drives show the P600Q-D316 capable of delivery a very high performance over 10-Gigabit. Add in the end-to-end hardware redundancy and high expansion potential and you have an affordable IP SAN appliance suited to hosting business critical storage
Verdict
SATA support does require optional MUX boards but there’s little else to criticise the P600Q-D316 for. It’s an affordable IP SAN solution with high levels of redundancy, good expansion potential and top performance over 10-Gigabit.
Chassis: 3U rack
Storage: 16 x hot-swap LFF/SFF SAS 2 drive bays
Power: 2 x 500W hot-plug PSUs
Cooling: 2 x hot-plug fan modules
Dual active/active RAID controllers each with:
CPU: 1.73GHz Intel Xeon C3528
Memory: 4GB DDR3 with battery backup module
Array support: RAID0, 1, 10, 3, 5, 6, 10, 30, 50, 60, N-way
Network: 2 x Gigabit, 2 x 10GbE SFP+, 1 x management
Other ports: SAS expansion port
Management: Web browser, QCentral
