Why you should use Free NAS for Local Backup server
This ease-of-use does not mean, however, that FreeNAS is a black box that ties the hands of experienced system administrators. The full power of the FreeBSD shell environment is a click away in the GUI or accessible through SSH for many diagnostic and administrative tasks. Ultimately, FreeNAS makes NAS deployment easier than ever but doesn’t get between you and the storage solution you need.
The ZFS file system at the heart of FreeNAS is designed for data integrity from top to bottom. RAID-Z, the software RAID that is part of ZFS, offers single parity redundancy equivalent to RAID 5, but without the traditional “write hole” vulnerability thanks to the copy-on-write architecture of ZFS. The additional levels RAID-Z2 and RAID-Z3 offer double and triple parity protection respectively. A software mirror RAID 10 equivalent option is also available for maximum performance. FreeNAS suggests a parity arrangement based on the number of available disks, and allows you to override that suggestion with a custom one. Intelligent read and write caches plus hot spares can be configured to maximize the performance and reliability of your storage solution.
Thanks to the copy-on-write design of ZFS, efficient, point-in-time snapshots of an entire pool or individual file system can be created at any time or on a regular schedule. Creating snapshots initially do not consume any data and are instantly created, allowing very granular policies to be created. Snapshots are also seamlessly exposed to protocols such as SMB, allowing Windows clients to browse “Previous Versions” of a file natively.