In Windows you have a graphical interface where you can determine which folder takes up how much space. Most Linux servers don’t have a graphical front end (i.e. no GUI desktop) because they take up valuable resources that must be used for your web server software. You may still have large file folders that Linux doesn’t use that might need cleaning up. This is especially true if you are running a VPS or dedicated server with SSD drives, which are very fast but also expensive per GB and therefore you usually get less space. It’s very important to keep your server clean so you don’t waste money on storing unnecessary files!
This article will show you how to use ncdu to determine the size of folders on your system, there is an alternative method using tree and du.
Using ncdu to identify a large folder
Install ncdu on Debian or Ubuntu with this command
sudo apt-get install ncdu
On CentOS 6.8 and above
yum install epel-release
yum install ncdu
Enter the root directory (not the home directory of the root user / root)
cd /
Execute ncdu
ncdu
Once executed, ncdu will scan the entire file system, the interface will be shown below.
Using ncdu, you get the menu. The largest folders are displayed in ascending order from largest to smallest.
The idea is to show the large folders first, then show the subdirectories again in ascending order.
After entering a subfolder, you can see which of these subfolders are taking up the most space.
--- / --------------------------------------------------------------------------
10.4 GiB [##########] /var
8.1 GiB [####### ] /root
2.2 GiB [ ] /usr
2.2 GiB [ ] /lib
2.1 GiB [ ] swapfile
134.5 MiB [ ] /boot
67.6 MiB [ ] /tmp
34.7 MiB [ ] /run
12.8 MiB [ ] /bin
11.4 MiB [ ] /sbin
6.3 MiB [ ] /etc
e 4.1 KiB [ ] /lost+found
8.1 KiB [ ] /media
2.1 KiB [ ] /lib64
e 2.1 KiB [ ] /srv
e 2.1 KiB [ ] /snap
e 2.1 KiB [ ] /opt
e 2.1 KiB [ ] /mnt
e 2.1 KiB [ ] /home
. 0.0 B [ ] /proc
0.0 B [ ] /sys
Total disk usage: 28.0 GiB Apparent size: 28.0 GiB Items: 354728
We use the arrow to select folders and use q to exit and delete unneeded files
Here are the commands to control ncdu, you should be able to get using the arrow keys to move and q to exit
qncdu helpqqqqqqqqqqqqqqqqq1:Keysqqq2:Formatqqq3:Aboutqqk
1.1 Gix x
164.8 Mix up, k Move cursor up x
20.7 Mix down, j Move cursor down x
7.7 Mix right/enter Open selected directory x
812.0 Kix left, <, h Open parent directory x
56.0 Kix n Sort by name (ascending/descending) x
56.0 Kix s Sort by size (ascending/descending) x
12.0 Kix C Sort by items (ascending/descending) x
8.0 Kix d Delete selected file or directory x
8.0 Kix t Toggle dirs before files when sorting x
e 4.0 Kix g Show percentage and/or graph x
4.0 Kix -- more -- x
4.0 Kix Press q to close x
4.0 Kimqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqj
This is by far the fastest way we’ve learned to identify large folders on Linux systems.
Tree and du
On Ubuntu and Debian systems
sudo apt-get install tree
On CentOS
yum install tree
You can run this command in a folder that you know or suspect might be large
tree --du -d -shaC | grep -Ev '( *[^ ]* ){2}[' | more
Press space to go to the next page and use q to get to the additional pages screen.
