Cheap SANs boast high-end features

This is a good time to be buying a midrange storage-area network. Gigabytes per dollar is dropping, throughput per dollar is increasing and affordable systems are delivering sophisticated features that used to be reserved for the high end of the market.

Storage systems typically consist of three logical parts that may be in the same box or in different ones – a chassis that holds disks, a physical controller that interfaces the disks with the storage protocol, and a software management system. There are plenty of options: the chassis may support 12 to 48 SATA, SAS, Fibre Channel or SCSI disks, the controllers include hardware RAID at many levels, and vendors may support Fibre Channel, Ethernet or both.

We looked at four systems that represent a cross-section of the mid-range SAN market today:
• Compellent Storage Center 4.0, the highest-priced system of the group at just over $68,000. Compellent supports both Fibre Channel and Ethernet.
• Dell EqualLogic PS4000, an iSCSI-only product at $17,000.
• HP StorageWorks 2000sa G2 Modular Smart Array, a Fibre Channel only product at $13,000.
• And a build-it-yourself combination of Promise Technology vTrak E610f with Datacore's SANMelody 3.0 storage software, a Fibre Channel and Ethernet system that runs less than $10,000.

You can expect some things from virtually any SAN system these days, including easy setup and quick integration into your existing data center. The high-end features that used to be the domain of expensive Fibre Channel systems are now available in the midrange systems we tested.

In fact, the Promise/Datacore system, the least-expensive product we tested, not only had all the features of higher-end products, it includes integration with VMware and some other features that the more expensive products have on their road maps, but not on shipping products.

So why buy the more expensive products? Peace of mind, primarily. For example, the Promise/DataCore system has no integrated support or warranty – you buy the system, some disks, a server to run the DataCore software on, and the assorted infrastructure parts (switch, cabling), and put it together yourself.

Click to see: Net results

If you can't get it to work as expected, each of the six or more vendors involved is likely to point fingers at the others. If you're not sure what you're doing, it's easy to get SATA drives that really shouldn't be used in a RAID array, for instance. And optimizing performance is not necessarily a simple thing – buying a complete system gives you components designed to work together.

The systems we tested are not direct competitors; they are all aimed at different parts of the storage market. In addition, each vendor offers a wide range of configurations that can produce systems from basic and inexpensive to very high performance and feature rich.

This test demonstrates the wide variety of functionality and performance available. For example, if you're looking for a very low cost iSCSI system, an EqualLogic system can be purchased with eight drives for around $10,000, while a high-end EqualLogic system can run $100,000 or more. The other vendors also offer a similarly wide array of options in the price/performance spectrum.