Thin provisioning allows you to create a volume that appears to be larger than it really is. It's a feature designed to allow you to add physical capacity only when you actually need it, without having to resize volumes or file systems. Microsoft supports this type of volume creation with Windows Server 2012. The ReadyData 5200 provides its own thin-provisioning capability for iSCSI volumes, making it possible to provision an iSCSI volume that presents itself as a particular size without the requirement to immediately allocate the full amount of physical disk space.
To test performance, I ran Iometer on an HP BL660c blade server with four Intel E5-4610 CPUs and 64GB of memory. I used the same Iometer configuration file (OpenPerformanceTest32.icf available at vmktree.org) as in my tests of the ReadyNAS 4220 and its competitors. This test configuration uses four different scenarios to measure sequential I/O and random read/write performance.
Although the ReadyData 5200 unit was equipped with a dual-port 10GbE NIC, I tested using a single 1GbE port in order to draw comparisons with the ReadyNAS 4220. The charts below show the results from the four tests against an SMB share and an iSCSI LUN on the ReadyData. The results for the ReadyNAS reflect the same four tests against an SMB share.
The numbers show iSCSI to be the faster interface for the ReadyData. Both volumes were created from the same RAID set, so the disk access should be about the same. Keep in mind this is the SMB 2.0 protocol as opposed to the new Microsoft SMB 3.0 protocol. Comparing the ReadyData and ReadyNAS results shows the obvious advantage of SSD caching.
The flash caches give the ReadyData significant latency and random access advantages over its ReadyNAS sibling. With flexibility to adjust the flash sizes and distribution to meet specific application needs, you can tailor the ReadyData device to just about any workload. Add to that the ability to take unlimited snapshots and roll back to any instant in time, and the ReadyData will be much more appealing to a small or medium-size enterprise looking for a general-purpose storage system.
Netgear prices the ReadyData based on the types and numbers of drives in the system. My review unit as tested would cost $18,850 at full retail, but can be had for considerably less through any number of different distributors. If you choose to purchase drives separately, the ReadyData can be had sans drives for less than $6,000.
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