Computer data-protection provider Unitrends, Columbia, S.C., says it's acquired Philadelphia-based data disaster recovery system developer PHD Virtual (which makes the ReliableDR platform), for a price it won't name.  Statement here.

The deal will join PHD Virtual's 70 workers, under boss James Legg, to Unitrends and its boss, Mike Coney, serving a total of 10,000 customers in multiple countries. Both companies are controlled by investor Jeff Horing's Insight Venture Partners, New York. Together they'll grow faster, Insight managing director Mike Triplett said in a statement.

Insight and Citrix Systems bought control of PHD in 2010. PHD's staff has expanded to 70 from around 20 in 2009 after beefing up its salesforce. Founder Ron McKelvey and his partners named the company PHD Virtual back in 2006, joking that none of them had actual Ph.D. degrees but they all had equivalent programming development experience.