ZFS vs Btrfs
Shared Design, Different Histories
ZFS vs Btrfs is a comparison of two copy-on-write file systems. Both add checksums, snapshots and built-in volume management to Linux and other systems. Both protect against silent corruption, but they differ in maturity, RAID support, licensing and resource needs.
ZFS has a long history in enterprise storage and was developed at Sun Microsystems. It is widely used on storage servers and has years of production experience behind its features. For a closer look at its design, see what ZFS is.
Btrfs was developed for Linux and has been part of the Linux kernel for many years, so it is readily available on most Linux distributions.
RAID Support and Stability
ZFS provides mirrors and RAID-Z as core parts of its pool design. These layouts are well tested and widely deployed, and they are the normal way to add redundancy to ZFS storage.
Btrfs has built-in RAID profiles for mirroring and striping, and its RAID 0, 1 and 10 modes are widely used. Its parity modes, RAID 5 and RAID 6, have had known problems for a long time, and the Btrfs project advises caution with them. Where parity-based redundancy matters most, ZFS has the more established record.
Licensing, Memory and Administration
ZFS is distributed under the CDDL license, which is not compatible with the Linux kernel's GPL. That is why ZFS on Linux comes as an add-on module rather than part of the kernel. Btrfs is under the GPL and ships with the kernel, so it needs no extra packages on most distributions.
ZFS uses a large share of RAM for its adaptive read cache, while Btrfs generally has a lighter memory footprint. The two also use different tools: ZFS has its own zpool and zfs commands, while Btrfs is managed with the btrfs utility alongside standard Linux tools.
Choosing for a Desktop Versus a Storage Server
A developer's Linux workstation with a single SSD might use Btrfs. Some Linux distributions offer it as an installer option, and it gives snapshots without extra packages.
A dedicated storage server with a dozen disks and a need for large, long-lived pools usually points to ZFS. Its mature RAID-Z layouts and well-documented scrub process suit that environment. Traditional Linux file systems take a different approach, as shown in ext4 vs XFS.
Frequently asked questions
Is Btrfs ready for production use?
Btrfs is used in production by many people, especially with single-disk and mirrored setups. Its parity RAID modes carry known risks, so they are generally avoided in production. Whether Btrfs suits you depends on the features you need and on the supported versions of your distribution.
Can ZFS and Btrfs read each other's disks?
No. They use different on-disk formats, so a pool or file system created with one cannot be mounted by the other. Moving data between them means copying the files through a normal file system interface or restoring them from a backup.