This tool can show you what folders have the most changed data between snapshots. Simply run:
btsdu -p /snapshots/old_snapshot /snapshots/new_snapshot
You will get a navigable breakdown in a NCDu interface.
ncdu 1.13 ~ Use the arrow keys to navigate, press ? for help
--- /home/roman ---------------------------------------------------
/..
42.5 MiB [##########] /.config
23.2 MiB [##### ] /.IdeaIC2017.2
12.3 MiB [## ] /.vscode
10.0 MiB [## ] /projects
9.5 MiB [## ] /.thunderbird
297.3 KiB [ ] /.local
20.0 KiB [ ] /.java
e 8.0 KiB [ ] /.bash_history
4.0 KiB [ ] /.pulse
e 293.0 B [ ] /.bashrc
Use the Rust package manager, cargo:
cargo install btsdu
If the cargo bin directory is in your path, you can run `btsdu right away. You
will also need NCDu (should be packaged by your distribution) for proper display
of the results.
- Shows uncompressed size
- Does not take into account reflinked files/extents and hardlinks
- Does show disk usage, just the actual data (called apparent size in NCDu). The on-disk and apparent sizes shown will be equal.
The tools uses btrfs send to get difference between two snapshots and then
builds up file-by-file summary of the size of changed data. The output is
printed in format understood by the NCDu display tool.
Naturally it is possible to use a a btrfs send/receive stream dump from your own
source, see --help for that. It is also possible not to run NCDu and just show
the underlying data. It is in pretty reasonable JSON format that can be
processed further.