#du #sh #dup #filesystem #cache

app du-dup

A minimal, fast alternative to 'du -sh'

1 unstable release

Uses old Rust 2015

0.2.0 Nov 1, 2018

#12 in #du

24 downloads per month


176 lines


Build Status

A minimal, fast alternative to du -sh.

dup is a very simple program that computes the total size of the current directory. It is a parallelized version of du -sh. On my 8-core laptop, it is about nine times faster than du for a cold disk cache and more than twice as fast on a warm disk cache.

> dup
14.56 GB (14556806983 bytes)


The following benchmarks have been performed with hyperfine on a moderately large folder (15GB, 100k directories, 400k files). Smaller folders are not really of any interest since all programs would finish in a reasonable time that would not interrupt your workflow.

In addition to du and dup, we also add tin-summer (sn) and dust in our comparison. Both are also written in Rust and provide much more features than dup (check them out!). The optimal number of threads for sn (-j option) was determined via hyperfine --parameter-scan.

Cold disk cache

sudo -v
hyperfine --prepare 'sync; echo 3 | sudo tee /proc/sys/vm/drop_caches' \
    'dup' 'sn p -d0 -j8' 'du -sb' 'dust -d0'

(the sudo/sync/drop_caches commands are a way to clear the filesystem caches between benchmarking runs)

Command Mean [s] Min…Max [s]
dup 1.729 ± 0.012 1.717…1.756
sn p -d0 -j8 9.778 ± 0.098 9.587…9.904
du -sb 16.016 ± 0.067 15.923…16.147
dust -d0 19.845 ± 0.466 19.428…20.948

Warm disk cache

On a warm disk cache, the differences are smaller:

hyperfine --warmup 5 'dup' 'sn p -d0 -j8' 'du -sb' 'dust -d0'
Command Mean [ms] Min…Max [ms]
dup 465.9 ± 14.7 446.5…487.4
sn p -d0 -j8 596.4 ± 12.2 579.2…615.9
du -sb 1100.3 ± 20.5 1086.9…1153.0
dust -d0 3560.1 ± 27.8 3521.7…3612.8


On Debian-based systems

wget "https://github.com/sharkdp/dup/releases/download/v0.1.0/dup_0.1.0_amd64.deb"
sudo dpkg -i dup_0.1.0_amd64.deb

On other distrubutions

Check out the release page for binary builds.


~143K SLoC