ZFS Snapshots are more than just local backups – they can be used to create remote backups as well. Replicating snapshots of the filesystem to a remote ZFS filesystem creates a complete duplicate there. Furthermore, additional snapshots of the same filesystem can be sent incrementally, reducing the size of each backup to the changes that were made between snapshots. In case of catastrophic damage to a local ZFS filesystem (such as disk failure in excess of parity protection or irrecoverable log device failure), any backed-up snapshot can be sent to a new ZFS filesystem, recovering all data up to that backup.
ZFS is designed for data integrity from top to bottom. RAID-Z, the software RAID that is part of ZFS, offers single parity protection like RAID 5, but without the “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 option is also available. The FreeNAS Volumes screen lists each possible parity arrangement based on the number of disks you select when creating a new volume.
Every ZFS filesystem is also verified with checksums from top to bottom to ensure data integrity. If inconsistencies are found, parity blocks can be used to repair corrupt data. A regular scrub is turned on by default and can be rescheduled or configured from the web interface.
FreeNAS is the first and only open source project to offer encryption on ZFS volumes! A simple encryption option is available during volume creation. For additional security, users have the options of adding a passphrase or initializing a volume with random data. ZFS Volumes encrypted by FreeNAS still use ZFS version 28, so interoperability with other ZFS implementations is not impacted – the only restriction is that only FreeNAS and FreeBSD can import encrypted volumes.
Encrypted volumes can only be read by FreeNAS systems in possession of the master key for that volume. Encryption allows for confidence when retiring and recycling hard drives because the drives no longer need to be wiped provided the keys are obliterated.
Thanks to ZFS, snapshots of the entire filesystem can be made and saved at any time. As long as a snapshot exists, administrators can access files as they were when the snapshot was made.
Snapshots can be made on a one-off basis or scheduled as a cron job from the web interface. At any time, the entire filesystem can be rolled back to the most recent snapshot. Older snapshots can be cloned and accessed to recover data from that version of the filesystem. From the web interface, users can see how much space a particular snapshot is occupying on the volume and delete, clone, or roll back to individual snapshots as needed.
File sharing is what FreeNAS® does best. Every major operating system is supported with SMB/CIFS (Windows file shares), NFS (Unix file shares) and AFP (Apple File Shares) as well as FTP, iSCSI, and other methods of sharing data over the network available.
Most operating systems, including Windows, Mac OS X, many Linux distributions, and PC-BSD® can connect using SMB shares with little or no additional configuration needed on the client side. Most Unix-like operating systems support connecting with NFS out of the box, and free clients are widely available. AFP is primarily used by Mac OSX and is well suited for a network environment that only connects with Macintosh clients. FreeNAS® also supports Time Machine backups with a few minor tweaks on the system being backed up.
If FreeNAS has one goal, it’s simplifying complex administrative tasks for as wide a user base as possible. Every aspect of a FreeNAS system is designed to be managed from a Web User Interface. From volume creation to permissions on individual shares, users can perform every task without missing a critical step or encountering a silent failure.
Of course, the FreeNAS Team knows we can’t think of everything. Many services have advanced configuration options available from the Web User Interface. The full power of the FreeBSD shell environment is also available just a click away or through SSH. Ultimately, FreeNAS makes NAS deployment easier than ever but doesn’t get between you and the solution you need.
FreeNAS® supports the core features of a NAS appliance out of the box. However, many users like to enhance their NAS appliance with third party software for media streaming, alternative protocols, or web applications.
To make sure your NAS can do everything you want, FreeNAS offers a third-party plugin system based on the FreeBSD jails system and the PBI system from PC-BSD. The plugin system isolates third-party software from the core operating system but allows plugins access to user-specified directories and configuration from the main Web User Interface.