HP and IBM are slugging it out over I/O virtualisation claims.

The row started when IBM released an I/O virtualisation tool called Open Fabric Manager last week, claiming it was a step up from HP's Virtual Connect as IBM used open technology that was compatible with switches from multiple vendors. HP fired back, saying Virtual Connect could support "any industry standard" switch, and claimied that IBM's technology fell short of the features offered by HP.

"IBM states that Open Fabric Manager supports Ethernet and Fibre Channel technologies from vendors like Blade Network Technologies, Brocade, Cisco, Emulex and QLogic, while HP Virtual Connect can only be used with a proprietary HP switch," said HP in a statement. "The fact is, HP Virtual Connect can attach to any industry-standard Ethernet or NPIV enabled Fibre Channel switch, greatly simplifying networking."

I/O virtualisation automates the process of assigning I/O addresses, making it easier to move workloads from one blade server to another. IBM lets users manage up to 1,400 blade servers - 100 chassis consisting of 14 servers each. HP's latest release, the Virtual Connect Enterprise Manager, announced 12 November, supports up to 1,600 servers, and HP claims it provides easier management than its rival. "[IBM's] Open Fabric manager copies configurations from one enclosure to another, but it does not offer what most customers would define as central management of up to 100 enclosures," HP says.

Virtual Connect is simpler to use than Open Fabric Manager, writes analyst Joe Clabby in a report for Pund-IT Research. But IBM's technology has many advantages over HP's, Clabby writes.

Despite what HP claims, Clabby says IBM has embraced third-party network vendor switches rather than building its own proprietary device, as HP has done. This means HP's Virtual Connect integration with third-party technology "is not as feature/function rich as the IBM offerings," Clabby writes.

IBM has also done better than HP by offering automated failover capabilities, single sign-on, and a lower-cost product, he says.

"The only disadvantage I could find for IBM is that it has taken them a few years longer than HP to get their solution to market," Clabby states.