As more businesses and consumers sign up to services that operate in the cloud, so more companies working in this space continue to get attention from investors. The latest is Sonian, a specialist in cloud-based archiving and search services, which has picked up a C-round of $13.6 million. With the funding, OpenView Venture Partners becomes a strategic partner of Sonian. OpenView — you may recall — in March announced a new $200 million fund specifically for cloud and big data investments. Existing investors Summerhill Venture Prtners and Prism VentureWorks also participated, and this brings the total invested in Sonian to-date is now at $27 million. Worth pointing out, too, that one of Sonian’s other investors is Amazon, which participated in the company’s last round where it raised $9 million.