F5 Networks has agreed to acquire file virtualisation specialist Acopia Networks in a $210m cash deal that is expected to close on 14 September.

Acopia has around 20,000 customers worldwide. Its ARX series file virtualisation appliances will be integrated with F5's Big-IP load-balancing products and its TMOS architecture to help with application delivery over distributed networks. ARX was designed to streamline data migration/replication and automatically store data in tiered environments based on importance and regulatory requirements.

F5 chief executive John McAdam conceded that buying a storage specialist represents something of a new direction for a networking company, but he said he is confident that future demand for file virtualisation will justify the move.

"If you go back five years in the datacentre, we were talking about large unstructured databases, but the explosion of unstructured data through emails, PDFs and regulatory stuff has grown massively. This is a problem that will be faced by just about every Fortune 500 company," McAdam said.

Gartner research director Joe Skorupa believes F5's strategy is to allow individual files to reside on any storage device anywhere on the network while remaining accessible to every user. This concept closely resembles the file area network (FAN) model promoted by Brocade and other vendors.

"The key challenge today is that when you bring WAN optimisation to branch offices, the transition means copying a lot of data from a lot of remote servers to a much smaller number of centralised servers, which means you have to go out and touch every desktop and remap all the drives," added Skorupa. "File virtualisation software allows you to manage that transition more easily, in less time and at lower cost."