RE: compression disk space saving - what are your results?

[<guido_kuenne@gmx.de>]

> Subject: compression disk space saving - what are your results?
> 
> What are your disk space savings when using btrfs with compression?

I checked that for some folders when I moved from ext4 to btrfs. I compared
du with df** just to get some numbers. I use lzo since btrfs-wiki said its
better for speed.


Percent_saving=(1-df/du)*100:
47% (mostly endless text files, source code etc., total amount of data is
about 1TB)
2%-10% (for data which is mostly in the form of large (several hundred MB up
to fewGB) binary files, total amount is about 4TB)
23% (for something in between, total amount is 0.4TB)

Result indicate pretty clearly: large binary files are almost not compressed
- without understanding much of it that's what I would intuitively expect
(afaik lzo is dictionary based and those binary files have little for that).


** du -s on the folder I copied to the btrfs drive. df is the difference in
between a df before and after the copy. Based on casual checking results
were consistent with the space needed on the old ext4 drive.