LeftHand enhances thin provisioning

By Ann Silverthorn

—Enhanced thin provisioning is among the 20 new features added to Version 7 of LeftHand Networks' SAN/IQ software.

The company hopes to differentiate its thin-provisioning implementation from a growing number of vendors that are offering the technology in two primary ways, according to John Fanelli, LeftHand's vice president of marketing. For one, the company claims a capacity utilization rate of up to 97%. The second is the ability for users to automate administration functions, including a higher level of warning and alerts.

Another feature of SAN/IQ 7.0 is what the company refers to as a proactive self-healing SAN. As an example, Fanelli says that as drives get bigger, cheaper, and faster, more data is put at risk. The potential downside is if you have a drive problem there's more data at risk and it can take more time to repair the drive. LeftHand addresses that issue by guaranteeing that its systems will read every block of data on the SAN at least every 28 days. When SAN/IQ finds an error, it can fix it by comparing it to a replica of the data.

"If an error were encountered during a drive rebuild, that error would be on the second copy of the data, and that would cause problems for the drive rebuild," says Fanelli.

Another aspect of keeping the SAN healthy is to maintain high performance over time. As a volume gets older and fills up, performance degrades. It could happen because it spans multiple LUNs or the SAN is fragmented, so LeftHand provides a drive defragmenter as well as a data alignment feature that puts data in an optimum position for performance.

"We realign the data on 8MB boundaries because that's the optimum size of the stripe for our clustered architecture," says Fanelli.

In a demonstration, Fanelli displayed the thin-provisioning aspect of the new version of SAN/IQ. The demo showed 8GB of storage, of which 5.5GB was provisioned for volumes and 2GB for snapshots. Graphically, the volume was actually configured to support 26.5GB, even though physically it only supports 8GB. Fanelli says that this not only reduces acquisition costs, but users can buy more storage when they need it?and storage prices are dropping.

"For some customers, seeing that 27GB on an 8GB capacity is a little daunting," says Fanelli, "so we provide alerts and warnings at 90% and 95% full. We also provide guidance as to what the user's options are, so they can change their snapshot schedule, delete some snapshots, or delete some storage."

Pricing for SAN/IQ varies based on capacity, drive type (SAS or SATA), and other factors. But Fanelli says users can start with a SAN that includes thin provisioning, synchronous and asynchronous replication, management software, and 6TB of capacity for about $28,000.

This article was originally published on August 01, 2007