Despite a revenue slump of nearly a fifth in 2009’s second quarter, the global external disk storage system market still contains areas of impressive growth, research has claimed.

According to IDC’s Worldwide Disk Systems Quarterly Tracker, global external disk revenue dropped by 18.3 per cent annually in Q2 to $4.1bn (£2.5bn). The total disk storage market fell 18.7 per cent on Q2 2008 to $5.7bn.

But the markets for iSCSI SAN and FC SAN deployments worth up to $15,000 continue to grow healthily, posting annual revenue increases of 57.2 and 66.8 per cent respectively.

IDC storage systems research analyst Liz Conner said: “Customers continue to demand enterprise-level network storage at a more economically friendly price.”

The market for NAS deployments worth between $15,000 and $50,000 also grew 20.7 per cent on 2008’s second quarter. Conner claimed this growth was partly fuelled by end-user demand for file-level data generation.

Maston Daniel, sales and marketing manager for Leeds-based reseller SICL, said demand was continuing to grow for both NAS and SAN infrastructures.

“We are seeing a continuing need for storage and an increasing demand to virtualise that storage,” he said.

He added that interest in iSCSI technology was on the up. “In an iSCSI environment, people are trading off fast throughput for volume of storage,” he said.

Des Lekerman, joint managing director of managed services firm Eurodata, claimed SMEs and large enterprises were becoming interested in iSCSI.

“There is demand for iSCSI because it is low cost compared with fibre,” he said.

“But then some customers demand the reliability of fibre; it depends on what the application is.”

IBM inched ahead of HP as the world’s leading disk storage system vendor in Q2, with both holding 17.3 per cent of the market. HP endured a 28.4 per cent yearly sales drop. EMC, Dell and NetApp completed the top five.