Sun is falling behind in the storage market, according to the latest market report from Gartner. In an external controller-based market that has grown 11 percent in the past 12 months, Sun's share has dived by 17.4 percent.

The report states that worldwide external controller-based disk storage is now worth $3.54 billion. In this market, EMC is the leader with 23 percent, equating to $814.7 million, fractionally down over the year. HP comes second with a 6.2 percent growth. IBM is number three with a near 12 percent share. It grew faster than the market as customers bought its new DS8000 and DS6000 products.

Hitachi Data Systems, HDS, is in fourth place and it grew less than the market at just under ten percent. But HDS did better than the figures suggest because both HP and Sun resell its TagmaStore product. The Gartner figures exclude this OEM revenue from HDS' market numbers. Gartner analysts think HDS needs to sell more mid-range disk arrays - which is exactly where HDS is beefing up its product line.

Dell comes fifth but is the fastest-growing vendor with a run-away 35.8 percent rise in revenue. This vindicates its decision to enter the storage market and sell the EMC AX100. It has overtaken Sun in market share terms. So too has number six vendor NetApp, which grew its revenue 27.2 percent. Gartner's VP for storage research, Roger Cox, said: "NetApp's success can be attributed to its single management platform, simple product lines and effective excecution on unified storage serving various applications."

Sun's performance was dismal. Its revenue dived by 17.4 percent and it lost share, moving from number five in the market to number seven with just 5 percent of the revenue. Sales of its resold TagmaStore (SE9000) declined and the 6920 mid-range system was launched after the survey period. In terms of disk storage sales Sun would be better off if it bought Network Appliance. It can hope that, if as expected, it takes the new HDS mid-range arrays then its sales will improve substantially.