virstoVirtual storage software startup Virsto announced that it closed a $12 million second round of funding led by InterWest Partners and that it had acquired Melbourne, Australia-based EvoStor.

Both the new investment and the acquisition will help drive growth, product development and expand industry partnerships, according to Virsto.

Virsto offers products to manage storage issues arising from server virtualization. It has partnerships in place with Microsoft and Citrix, and plans to expand its partner ecosystem later this year.

The Mountain View, California-based company closed its $7 millon first round of funding in June 2009 and has raised over $20 million total funding to date.