Fault tolerance is a feature of the Linux Btrfs file system. A Btrfs partition disk will make a copy of the file before storing it after a user makes changes to it. It's a type of "shadow copying," in which files are copied to maintain their original data each time they are saved by the user rather than being rewritten on disk. Administrators can provide fault tolerance and failover in the event that a copy of a saved file becomes damaged by using Btrfs.

The two greatest benefits of Btrfs are fault tolerance and copies of stored files. Additionally, Btrfs provides subvolumes for administrators who wish to create a volume for the operating system and another volume for user data, as well as data compression to lower the amount of storage space needed for stored files. If the attacker can only access the user volume, the latter offers greater security against malware attacks.

The two drawbacks of Btrfs are its lack of native encryption capabilities and its storage restrictions in comparison to ZFS. Administrators have a workaround because Btrfs encryption is provided by third-party providers. The shadow copies require the extra storage capacity.