btrfs-filesystem
Manage btrfs filesystems.
TLDR
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 [path/to/file]
Defragment a directory recursively (does not cross subvolume boundaries)
$ sudo btrfs filesystem defragment -v -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 --summarize [path/to/directory]