iSCSI technology is entering the mainstream as growing numbers of enterprises consider the storage alternative for its lower costs and management simplicity, analysts say.

The technology lets blocks of storage data be transported over Gigabit Ethernet and is easier and less expensive to install than Fibre Channel. Because it runs over Gigabit Ethernet networks, iSCSI doesn't require host bus adapters in servers and Fibre Channel switches. Nor do IT administrators, for the most part, need to have special knowledge and training in storage technology to deploy iSCSI.

According to IDC, while iSCSI today accounts for only a 3 percent share of external disk storage, the research firm expects it to reach more than 20 percent by 2010.

Enterprise Strategy Group (ESG) says that more than 20,000 customers have deployed iSCSI. The research firm surveyed 500 IT managers and found that 17 percent are using iSCSI in production environments and an additional 20 percent plan to implement the technology.

Lower costs and iSCSI's ease of management are among the factors driving adoption -- and not only among small and midsize businesses. Nearly 20 percent of businesses with 20,000 or more employees have deployed iSCSI, ESG reports.

Meanwhile, as shipments of iSCSI storage products have started climbing, start-ups specializing in iSCSI have emerged, such as Sanrad, LeftHand Networks, Intransa and EqualLogic.

EqualLogic, by its last count, has more than 2000 customers. EMC, meanwhile, added iSCSI capability to its midrange Clariion arrays and to its high-end Symmetrix DMX storage systems. Network Appliance, the leader in network-attached storage systems, has logged more than 30 percent market share for iSCSI systems shipped in 2006, according to IDC.

For its part, Sanrad claims more than 600 customers are using its iSCSI technology, and this week the vendor introduced a midrange iSCSI switch. Sanrad's V-Switch 3400 is a 3-port iSCSI switch with four Fibre Channel ports. The V-Switch has dual hot swappable power supplies and is managed via SNMP, a graphical interface and a command-line interface. It supports as much as four P-bytes of storage capacity and starts at US$26,000.