This whitepaper discusses how filers may be used to solve the data management problem in CDNs. The fast, simple and reliable appliance design for NAS is optimized for rapid data transfer between the user and disk over the network. Filers are very well suited for back-end storage in a CDN because of the following key features. A Snapshot is a read-only image of the filesystem that can be accessed online for safe backups and easy restores. Snapshots require low overhead because WAFL's intelligent design replicates filesystem metadata instead of replicating the filesystem data.
Users can restore data themselves by simply accessing the snapshot directory and copying files over.
SnapRestore allows the entire filesystem to be restored to a previous snapshot in minutes. Data redundancy makes SnapMirror a key feature for Disaster Recovery. Additional benefits are low filesystem overhead because of asynchronous transfers and high efficiency because only changed blocks are sent over the wire. A clustered system offers full redundancy, with no single point of failure. Takeovers take very little time because filers can reboot very quickly.