As the name indicates, file storage is supported by some form of filesystem that stores files and directories. In the traditional storage scenario, file storage is normally provided via servers acting as file servers or through the use of network-attached storage (NAS). File-based storage can be provided over several protocols and can sit on several different types of filesystems.
The two most common file-access protocols are SMB and NFS, which are widely supported by many clients. SMB is traditionally seen as a Microsoft protocol, being the native file-sharing protocol in Windows, whereas NFS is seen as the protocol used on Unix-based infrastructures.
As we shall see later, both Ceph's RBDs and its own CephFS filesystem can be used as a basis to export file-based storage to clients. RBDs can be mounted on a proxy server where a local filesystem is then placed on top...