Is iSCSI storage right for you?

The main points to consider when choosing between Internet SCSI (iSCSI) and Fibre Channel boil down to two things: cost and performance.

"Typically, the trade-off we see people making is between the lower cost associated with iSCSI vs. the higher performance associated

with Fibre Channel," said Steve Krauss, business operations manager for enterprise storage at GTSI Corp.

Fibre Channel gear has throughput of 2 gigabits/sec, and the industry is now transitioning to 4 gigabits/sec technology, according to vendor executives. Meanwhile, iSCSI products currently support 1 gigabit/sec speeds.

So if you are looking for the highest possible performance, iSCSI may not be the answer. Large data center environments, for example, demand high availability and high performance, said Frank Berry, vice president of corporate marketing at QLogic Corp. "That clearly points toward

Fibre Channel."

On the other hand, some applications don't demand the level of performance that Fibre Channel delivers, said Dan Smith, enterprise technology consultant for GTSI's storage technology team. In those cases, organizations may opt for an iSCSI solution to get networked storage at a lower cost.

However, the cost savings of iSCSI may not be what you expect. Hardware costs are generally lower with iSCSI vs. Fibre Channel, but the gap is narrowing. Berry said the technologies will even out in early 2005.

The greatest savings with iSCSI may stem from information technology workers' fluency in Ethernet and TCP/IP. With iSCSI, you won't have to hire a Fibre Channel storage-area network guru or train staff on a new technology. "It really gets down to the familiarity factor," Berry said.

Another iSCSI consideration: security. Mark Thoreson, director of technical sales at solution provider AC Technology Inc., said that area still needs to be fully addressed. Although IP Security rules are being written around iSCSI, Thoreson said he would hesitate to put "mission-critical data on this technology until it is really proven."

Until then, he suggests using iSCSI to back up data via dedicated circuits as a way to employ the technology and limit exposure.