btrfs

Create subvolume

$ sudo btrfs [[su|subvolume]] [[c|create]] [path/to/subvolume]

$ sudo btrfs [[su|subvolume]] [[l|list]] [path/to/mount_point]

$ sudo btrfs [[f|filesystem]] df [path/to/mount_point]

$ sudo btrfs [[qu|quota]] [[e|enable]] [path/to/subvolume]

$ sudo btrfs [[qg|qgroup]] [[s|show]] [path/to/subvolume]

btrfs [subcommand] [options] [args]

check
    Check filesystem integrity and repair issues

filesystem
    Manage filesystem: df, resize, defrag, sync, usage

subvolume
    Create, delete, list, snapshot subvolumes

device
    Add, remove, delete, scan devices

balance
    Balance data/metadata across devices

scrub
    Scrub filesystem for data errors

property
    Show or change properties like compression

qgroup
    Manage quota groups

send
    Send subvolume data stream for backups

receive
    Receive subvolume stream

rescue
    Superblock, chunk-tree recovery

-v, --verbose
    Increase output verbosity (repeatable)

-q, --quiet
    Suppress non-error messages

--help
    Show help for command or subcommand

--version
    Display version information

Btrfs (B-Tree File System) is a modern, copy-on-write filesystem for Linux, featuring snapshots, subvolumes, built-in RAID, compression, quotas, and data integrity checks via checksums. The btrfs command-line tool manages Btrfs filesystems and their components. It supports operations on mounted or unmounted filesystems, including creating/deleting subvolumes and snapshots for efficient backups, adding/removing devices in multi-device setups, balancing data across devices, scrubbing for errors, defragmentation, quota management, and integrity checks.

Designed for scalability and reliability, Btrfs addresses limitations of traditional filesystems like ext4 by providing atomic updates, transparent compression (zlib, lzo, zstd), deduplication, and send/receive for incremental transfers. It's widely used in servers, NAS, and desktops, though some advanced features require careful configuration.

The command uses subcommands for specific tasks, with global options for verbosity and quiet modes. Always unmount filesystems before major operations like checks unless specified otherwise.

Btrfs RAID5/6 modes are unstable and unsupported for production; backup data before balance/scrub; avoid mixing SSD/HDD without profiles; kernel versions matter for stability.

Snapshots/subvolumes: O(1) creation; RAID 0/1/10 stable, 5/6 experimental; Compression: lzo/zstd; Dedup via reflinks.

Use compress=zstd, space_cache=v2, ssd for optimization; degraded for missing devices.

Initiated by Chris Mason at Oracle in 2007; merged into Linux kernel 2.6.29 (2009). Evolved with features like quotas (2012), compression (2013), RAID56 (2014, unstable). Now mature in kernel 6.x, used in Fedora, openSUSE.

mkfs.btrfs(8), btrfsck(8), btrfstune(8), mount(8)