Btrfs tips and tricks

A collection of commands when using btrfs file system.

Compression

Recompress

To recompress files use:

btrfs filesystem defragment -r -v -czstd /home

 

Check compression

To check compression ratio of a file or directory use compsize

(https://github.com/kilobyte/compsize)

# compsize /home/user/some/dir/
Processed 40474 files, 24063 regular extents (24063 refs), 28464 inline.
Type   Perc   Disk Usage   Uncompressed   Referenced 
Data    65%         2.2G           3.4G         3.4G 
none   100%         1.7G           1.7G         1.7G 
lzo     65%          11M            17M          17M 
zstd    28%         493M           1.6G         1.6G