# 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}}`