tldr/pages/linux/btrfs-filesystem.md

btrfs filesystem

Manage btrfs filesystems. More information: https://btrfs.readthedocs.io/en/latest/btrfs-filesystem.html.

• Show filesystem usage (optionally run as root to show detailed information):

btrfs filesystem usage {{path/to/btrfs_mount}}

• Show usage by individual devices:

sudo btrfs filesystem show {{path/to/btrfs_mount}}

• Defragment a single file on a btrfs filesystem (avoid while a deduplication agent is running):

sudo btrfs filesystem defragment {{[-v|--verbose]}} {{path/to/file}}

• Defragment a directory recursively (does not cross subvolume boundaries):

sudo btrfs filesystem defragment {{[-v|--verbose]}} -r {{path/to/directory}}

• Force syncing unwritten data blocks to disk(s):

sudo btrfs filesystem sync {{path/to/btrfs_mount}}

• Summarize disk usage for the files in a directory recursively:

sudo btrfs filesystem du {{[-s|--summarize]}} {{path/to/directory}}

• Create a swap file:

sudo btrfs filesystem mkswapfile --size {{8g}} --uuid {{clear|random|time|UUID_value}} {{path/to/swapfile}}