US investor Storm Ventures and software vendor Informatica led the round, with existing investors Doughty Hanson Technology Ventures and The Dow Chemical Company also participating.
RainStor, whose products help companies organise large volumes of archived data for commercial or regulatory purposes, recently entered the US market, moving its headquarters from Gloucester in the UK to California.
The company is still registered in the UK and led by British entrepreneur John Bantleman, who has lived in the US for 18 years and joined RainStor (then called Clearpace) in 2004.
