HP announced today it's acquiring open-source cloud management company Eucalyptus and installing the startup's CEO, Marten Mickos, as head of the HP cloud division.

The deal amount wasn't disclosed, although Reuters heard it's less than $100 million, a pittance next to HP's $112 billion in revenues for the past 12 months. Eucalyptus had raised $55 million in three venture rounds.

The deal is expected to close by Oct. 31, the end of HP's fiscal year.

The arrival of Mickos — formerly CEO of MySQL — continues a chain of executive changes HP has been experiencing in the cloud and virtualization areas. As senior vice president in charge of cloud, he'll be replacing Martin Fink, who remains HP's CTO and the director of HP Labs.

Fink is also the leader of HP's new network functions virtualization (NFV) business. Bethany Mayer held that post, reporting to Fink, but last month she accepted the job as CEO of test-equipment vendor Ixia. Mayer's new job will start once Ixia is finished cleaning up its financial reports.

Eucalyptus' fabric controller targets private and hybrid clouds with an eye toward compatibility with Amazon Web Services. It would seem to fit with HP's stated strategy to promote its own hybrid-cloud service, Helion, which launched in May.

Thing is, Helion is OpenStack-based, and OpenStack has been a touchy subject for Eucalyptus. NASA and Rackspace started OpenStack in 2010 in response to Eucalyptus' perceived troubles with scaling, among other issues. As GigaOm and Wired point out, Mickos hasn't been particularly friendly to OpenStack in the past.

That's changing, at least on the surface. Mikos explained in an August blog posting that he wants Eucalyptus to become more of an OpenStack contributor. (HP already claims to be the top contributor to OpenStack Juno, the release due out this fall.) And he'll be keynoting at OpenStack Silicon Valley on Tuesday.

(Photo: Not Marten Mickos, just so you know.)