"They have all the components of being the dominant data center vendor," with storage, servers, management tools, networking and security, but need to combine it into something more than the sum of its parts, Kerravala said.

Cisco set the stage for that showdown with its entry into the server business through the Unified Computing System line, followed by its partnerships with EMC and VMware for storage and virtualization. HP and Cisco, along with IBM, Dell and others, now face off as would-be builders of entire data centers.

Haas' departure may have been part of an overall move by Apotheker to bring in his own team at HP, Kerravala said. Haas' replacement at the top of the networking division should be someone who has deep networking expertise, he believes. "Networking is a different discipline to compute. It's tough for compute vendors to get into networking, and vice versa," Kerravala said.

The IDG News Service