A network attached storage device for performing network attached storage operations with cloud storage services. The device comprises at least one network controller for communicating with a plurality of clients over a local area network (LAN) and with a cloud storage service (CSS) over a wide area network (WAN); a plurality of storage devices for locally storing data in the device; a CSS module for at least synchronizing between data locally stored in the plurality of storage devices and data stored in the CSS; and a processor for enabling the plurality of clients to perform file-based operations on the device using a file sharing protocol.