Test Score: 4.0 out of 5
Editor's note: This is a summary of our testing of this product, for a full rundown of how it fared in our testing across iSCSI SAN Server categories; please see our full coverage.
LeftHand Networks has a very different approach to scaling storage-area network bandwidth than other products we tested. LeftHand is a software company, and its SAN/iQ software is offered on many different platforms. LeftHand sent us six of its NSM 2120 Storage Nodes, which are HP DL320s storage servers running the LeftHand software. (LeftHand also sells Storage Nodes that are both larger and smaller than the NSM 2120, all based on OEM hardware.) Each of the NSM 2120s is in a 2U chassis and has a dozen, 300GB SAS drives.
What's unique about LeftHand Networks' approach is that its Storage Nodes scale up into a single, unified iSCSI server that still presents only a single IP address to the iSCSI fabric. This gives LeftHand a distinct performance advantage. In our case, we elected to evaluate only three of the NSM 2120s to make a more reasonable apples-to-apples comparison with the other devices we tested. Even with only three storage nodes, LeftHand was top performer in our speed tests as a result of its ability to make use of multiple storage nodes to serve data in parallel to our iSCSI initiators.
Although LeftHand brought high performance and a modest set of enterprise features to the table, it missed being a top performer overall in our evaluation because of its management client, which was difficult to use across several dimensions. Our critical complaint is that while LeftHand has done an admirable job at bringing together the multiple storage nodes into a coherent whole for providing virtual disk service, it has done a much less satisfactory job at unifying the multiple nodes when it comes to configuration and day-to-day management and monitoring tasks.
LeftHand also has to work against a costly architecture. Because LeftHand is combining powerful, independent units in each of its Storage Nodes, the price per gigabyte doesn't get lower the way that other iSCSI server prices do. LeftHand does have lower cost configurations than the one we tested, but you sacrifice some high availability and performance when you don't configure with multiple storage nodes. You certainly can get started for much less than our $100,00 configuration, but if you go with two nodes to get high availability, you don't get any more storage (because all must be duplicated for high availability). Our three-node configuration, a minimum for cost-effective high availability, was the most expensive iSCSI server we tested.
Overall, LeftHand has done an amazing job at taking independent devices and getting them to work together as a single iSCSI server, and gets great performance scalability because of its architecture; you just have to be willing to pay the high price for these things.