Tools to manage disk space usage on *NIX systems, including the powerfull ncdu, and how to use them.
df -hdu -sch /PATH/TO/FOLDER
# Example for current folder:
du -sch *
# List by file size (if `sort -h` is available on your system):
du -sch * | sort -hYou can add an alias sp='du -sch * | sort -h in your ~/.bashrc file.
ncdu is a useful program to manage disk space usage on *NIX systems. You can use it to find what folder take the most space or contains the highest number of files. When using ncdu, you can navigate folders in real time while tracking space usage. When you locate a folder that takes too much space, for example because it contains a high number of big, un-compressed files, you can switch to bash temporarily and solve the problem before coming back to ncdu.
The following sub-sections describe how to install and use ncdu.
ncdu can be downloaded from here : https://dev.yorhel.nl/ncdu
To install on your computer it, run the following (you may need to adapt for the version number):
tar xvfz ncdu-1.12.tar.gz
cd ncdu-1.12
./configure
make
sudo make installIf you need to install on a server where you do not have administrative rights, it may be easier to ask the system admin to do it for you.
To launch ncdu, open a bash terminal and move to a folder where you want to learn more about
disk space usage, then simply type ncdu in the terminal. You will be presented with a window that
looks like this:
ncdu 1.12 ~ Use the arrow keys to navigate, press ? for help
--- /home/username/Desktop/ncdu-1.12 ------------------------------
196.0 KiB [##########] configure
184.0 KiB [######### ] /src
52.0 KiB [## ] aclocal.m4
36.0 KiB [# ] /deps
32.0 KiB [# ] Makefile.in
24.0 KiB [# ] depcomp
16.0 KiB [ ] ncdu.1
16.0 KiB [ ] install-sh
16.0 KiB [ ] /doc
8.0 KiB [ ] compile
8.0 KiB [ ] missing
8.0 KiB [ ] ChangeLog
4.0 KiB [ ] config.h.in
4.0 KiB [ ] configure.ac
4.0 KiB [ ] README
4.0 KiB [ ] COPYING
4.0 KiB [ ] Makefile.am
Total disk usage: 620.0 KiB Apparent size: 529.3 KiB Items: 46
You can navigate the folders and files by using either the arrow keys or,
for the true 1337 among you, the vim movement keys. In the example screen
presented above, pressing down and then right would bring us in the src
foldler.
To quit ncdu, press the q key.
By default, ncdu shows the biggest folder or file at the top and then the rest by decreasing order of disk space used. This is very useful to find what files and folders are using the most space. In our example, we can see that the configure (196.0 KiB) and src (184.0 Kib) folders take up most of the space taken by the whole folder (620.0 KiB, seen at the bottom).
You can change what information is displayed in the ncdu window with the following keys:
- g: Change/remove the file size information style. Press multiple times to cycle.
- c: Show/hide the number of files in folders.
- t: Put folders before files. Press again to cancel.
- a: Toggle between apparent size and disk usage.
- e: Show/hide hidden or excluded files.
- i: Show information about selected item.
- r: Recalculate the current directory.
You can sort the folders and files in a different order than the default (by file size) by using the following keys:
- s: file size (default). Press again to reverse order.
- n: file name. Press again to reverse order.
- C: number of items. Press again to reverse order.
Sometimes, we run programs that create crazy amounts of files. By pressing c to show the file number by folder ane C to sort by number of files, we can locate these problematic folders and take appropriate action, whether to delete them or compress them into an archive.
WARNING!: Once you use this procedure, just like for the UNIX rm command, your files are gone forever!. Use with caution.
When you use ncdu to navigate to a folder, you can highlight a file or folder and
press the d key to delete it. ncdu will ask you if you are sure about deleting
that file or folder. If you press yes, the file or folder is gone, forever. There is
even an option to tell ncdu to stop asking you to confirm each deletion. For the
sake of your own sanity, DO NOT USE THIS OPTION!. It is altogether too easy to hit
the d key by mistake while you are browsing the folders with ncdu and to delete
important files and folders. You will not pardon yourself this mistake easily. Not that
I would know about this from first hand experience, of course...
Once we have identified a problematic folder, ncdu makes it easy to jump right in
that folder to solve the problem. Instead of copying the path, exiting ncdu, moving
into the folder of interest, taking action and then opening ncdu again, we can
switch to a bash session by simply pressing the b key. The present working directory
will be the directory we were visualizing in the ncdu window. We can then remove,
compress or archive files and folders as needed. When we are done, pressing Ctrl-D or
typing exit will bring us back to our ncdu session.
During a session, you can press the question mark (?) key to open the interactive
help menu. It is quite simple and looks like this:
ncdu 1.12 ~ Use the arrow keys to navigate, press ? for help
--- /home/username/Desktop/ncdu-1.12 --------------------------------
196.0 KiB [##########] configure
1┌───ncdu help─────────────────1:Keys───2:Format───3:About──┐
│ │
│ up, k Move cursor up │
│ down, j Move cursor down │
│ right/enter Open selected directory │
│ left, <, h Open parent directory │
│ n Sort by name (ascending/descending) │
│ s Sort by size (ascending/descending) │
│ C Sort by items (ascending/descending) │
│ d Delete selected file or directory │
│ t Toggle dirs before files when sorting │
│ g Show percentage and/or graph │
│ -- more -- │
│ Press q to close │
└──────────────────────────────────────────────────────────┘
4.0 KiB [ ] Makefile.am
Total disk usage: 620.0 KiB Apparent size: 529.3 KiB Items: 46
You can navigate the 3 subsections (1:Keys, 2:Format and 3:About) with the left and
right keys and scroll up and down with, you guessed it, the up and down arrows.
The vim keys work here too. To quit the help menu, simply press the q key.
ncdu's manual can be found here: https://dev.yorhel.nl/ncdu/man but, frankly, pretty much all you need to know is covered here or in the interactive help menu.
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