The iQstor iQ2880 does not offer every bell and whistle of the Compellent and Xiotech SANs, and it takes a bit more effort to set up, but it offers great performance, scales to 180TB with SATA drives, and starts at less than half the price of the other two systems. It is an excellent way to go if you don’t anticipate the need for the fancy features.

Xiotech Magnitude 3D 3000e

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The Magnitude 3D 3000e Storage System I tested consisted of several separate pieces: the Icon management appliance, one controller, one shelf of drives, and the TimeScale appliance that manages asynchronous replication, heterogeneous replication, and CDP (continuous data protection). The shelf included eight 73GB FC drives and eight 146GB FC drives. The Icon appliance is used to manage the controller. It seems a bit much to use a separate management appliance if you have only one controller, but it will manage many controllers just as easily.

The TimeScale appliance offloads compression and data encryption over the WAN link, removing that load from the controller and allowing replication between multiple controllers with ease. It also handles heterogeneous replication, allowing replication between storage systems from different vendors, whether SAN-attached or server attached, and provides continuous data protection, a journal-based form of replication that goes beyond the capabilities of standard synchronous or asynchronous replication.

On-site installation support is included, so most administrators will probably not see much of the installation process, which is probably for the best, since the combination of four or more separate pieces of hardware does introduce some complexity. The Icon interface for configuring volumes and other functions such as mirroring and synchronous replication is straightforward. It's not as wizardly as the Compellent system, but easy enough to work your way through. Figuring out whether to use the Icon interface or the TimeScale interface to set up some things like remote replication can also be a puzzle, although one you’ll quickly solve.

The Magnitude 3D supports ILM-style data migration through host-based software, which uses agents on each server to identify data that can be migrated from tier one to tier two or three. This is not as transparent as data migration in Compellent, which is handled in the controller with no server agents or additional load on the servers required. Nevertheless Xiotech provides some of the same functionality, albeit with more setup required.

The TimeScale appliance enables a number of features not available from Compellent. It provides compression, encryption, and deduplication of data sent over the WAN link, which both secures transmitted data and optimizes the use of the link. TimeScale can replicate data to other systems from other storage vendors, even allowing the use of server-attached storage. This means that a single TimeScale box can facilitate replication across the enterprise, between a widely disparate variety of storage systems. TimeScale also supports bandwidth limiting by connection, allowing the administrator to control both the amount of bandwidth consumed by remote replication or CDP and also the amount of server utilization for local replication. Server utilization can be a significant factor, because heterogeneous replication routes data through the server that the storage is attached to, rather than bypassing the server and routing data from one SAN device to another. This is the only way to make use of non-SAN storage, but it can introduce fairly heavy loads on the server, depending on the amount of data being replicated.