Midrange SANs master high-end features
Compellent, iQstor, and Xiotech combine sophisticated enterprise capabilities with amazing ease
The iQstor offers a rich set of features that includes thin provisioning, snapshots, mirroring, replication, and virtualization. Plus, not only is it easy to expand existing volumes, but an automated capacity growth feature allows the system to use available, uncommitted storage to automatically expand volumes that are nearing full capacity.
iQstor includes an agent that makes it easy to create point-in-time snapshots of open Exchange, Oracle, and SQL Server databases. The agents pause the database long enough for the iQstor to take simultaneous “group snapshots” of all active data volumes, ensuring that all open records are correctly copied. The snapshots can then be used to make tape backups or remote replicas without having to shut down the database for the duration of the backup.
As with the other two systems reviewed here, snapshots use pointers to accelerate snaps and save disk space, requiring just 10 percent to 20 percent of the space required for a full copy of a volume. The number of snapshots is not unlimited, but the limit of 126 snapshots per volume should be enough for most people.
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 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.