Compression Makes an Impression

The advent of disk-based backup systems is giving new life to an old technology: hardware-based compression.

Two component suppliers offer PCI-based cards that might soon appear in disk backup products. Startup Indra Networks Inc. is currently negotiating with disk backup vendors and expects at least one deal to materialize shortly, while semiconductor maker Comtech Aha Corp. is readying an April release of a board-level product that has upwards of 15 potential OEMs interested, according to company sources.Meanwhile, Quantum Corp. (NYSE: DSS) has been working on hardware-based "compression adapters" for its DX series of disk-backup systems and is expected to deliver that capability soon. Quantum already uses hardware compression for its tape libraries based on processors from Hifn Inc. (Nasdaq: HIFN).

To be sure, some disk-based products already use compression to reduce the amount of data stored on the device, typically on the order of 2:1 or 3:1 ratios. However, software-based techniques have ruled the day as a more cost-effective method.

Proponents of hardware-based compression, however, beg to differ. They say that offloading compression algorithms from the primary storage processor significantly improves performance from higher-latency software-based methods. That could be a boon to disk-based backup appliances.

"If you do compression in software, one of the key reasons to do disk-to-disk backup becomes diluted," says analyst Arun Taneja of The Taneja Group. "It takes away from the performance [advantage] of disk backup, so it's like you took one step forward and half a step back."Indra's StorCompress and Comtech Aha's forthcoming AHA-362-PCIX fit into the PCI slot of the storage device and integrate compression algorithms into the firmware in an effort to improve performance. These products are just making their way to the market now because of their complexity, say the vendors."To get the throughput you need for these products, you need multiple chips," says Sean Gettmann, sales engineer at Comtech Aha. "Doing the logic and load balancing for them is rather tricky and hard to set up."

Brett Mendel, Senior Analyst, Byte and Switch Insider