What is the easiest way to free space on a hard drive?

Question

My hard drive became full. I am looking for ways to locate the things that use most of my disk space. I played with cron once so it may have consumed a great deal of space, but really I have no clue.

I have backed up my things to CDs, but the system is still getting too slow. Perhaps I should reinstall everything, but whilst fixing the problem it doesn't address the cause.

Testing KamilMaciorowski's answer for ncdu

I run ncdu as root and get the following where I missed out the backup file in my system by other methods

--- /home/masi ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
   45.5GiB [##########]  backup_home_1.9.2016.tar.gz
   34.9GiB [#######   ] /Documents                                                                                                                                                                                 
    1.4GiB [          ] /Videos
    1.4GiB [          ] /.cache
    1.2GiB [          ] /Downloads
    1.0GiB [          ] /.config
  607.8MiB [          ] /Pictures
  487.0MiB [          ] /.matlab
  447.2MiB [          ] /Images
  406.1MiB [          ] /Desktop
   97.1MiB [          ] /.kingsoft
   58.4MiB [          ] /.local
   20.6MiB [          ] /.Mathematica
   13.3MiB [          ] /.mozilla
   ...

Answer 1

Linux tool ncdu is very convenient in my opinion. It's like interactive du.

Some features

• Text interface (ncurses); works via SSH, no Xserver needed.
• Still you can move within directory tree to find large dirs/files quickly.
• You can delete dir/file from within the program.

Screenshot

Well, kind of. There's no point in pasting picture, text will be enough:

ncdu 1.10 ~ Use the arrow keys to navigate, press ? for help                    
--- / --------------------------------------------------------------------------
    6,7GiB [##########] /usr
    3,4GiB [#####     ] /var
  553,1MiB [          ] /lib
  529,1MiB [          ] /opt
   35,1MiB [          ] /etc
   32,5MiB [          ] /home_old                                               
   16,4MiB [          ] /sbin
    9,9MiB [          ] /bin
    8,2MiB┌───ncdu help─────────────────1:Keys───2:Format───3:About──┐
    3,8MiB│                                                          │
    1,3MiB│       up, k  Move cursor up                              │
  500,0KiB│     down, j  Move cursor down                            │
  124,0KiB│ right/enter  Open selected directory                     │
   12,0KiB│  left, <, h  Open parent directory                       │
    8,0KiB│           n  Sort by name (ascending/descending)         │
@   4,0KiB│           s  Sort by size (ascending/descending)         │
@   4,0KiB│           C  Sort by items (ascending/descending)        │
@   4,0KiB│           d  Delete selected file or directory           │
    0,0  B│           t  Toggle dirs before files when sorting       │
>   0,0  B│           g  Show percentage and/or graph                │
e   0,0  B│                        -- more --                        │
>   0,0  B│                                     Press q to continue  │
>   0,0  B└──────────────────────────────────────────────────────────┘
>   0,0  B [          ] /home
>   0,0  B [          ] /dev
e   0,0  B [          ] /cpusets
e   0,0  B [          ] /cdrom
>   0,0  B [          ] /boot



 Total disk usage:  11,3GiB  Apparent size:  11,1GiB  Items: 289029             

Usage:

ncdu -x /foo/bar/mountpoint

Use sudo (and caution!) when necessary. The -x option is important, it makes ncdu stay within single filesystem (du has the same option). In the example (above) my /home is on a different partition than / where ncdu started, therefore it does not count – thanks to -x switch exactly.

Answer 2

"I played with cron once so it may have consumed my mass memory, but really I have no clue." No clue, you say? never would have guessed. :)

su -
cd /
du -s ./* | sort -n

• du shows disk usage, in blocks (1 block = 0.5 kilobytes, in all cases that matter to you.)

• -s means, "summary", so it gives only a total for each argument "./*" being the argument.

• piping it into sort -n means sort numerically. The larger numbers at the bottom.

• So, you'll get a list of directories with the ones using the most space at the bottom.

If that's not enough help, say you get:

60380   ./root
142468  ./etc
537716  ./var
627264  ./lib
5757600 ./usr
28859472        ./home

• and you see that ./home is the biggest piggy, ok, cd into /home, and do the same du -s | sort -n. Then you see who in /home is taking up space. (on a single user system, well, it's probably you.)

• Then cd into there, and do du -s | sort -n again.

Keep doing this until you find the culprit. When you find the culprit, you may say, oh yeah... that's my collection of hi-res renderings of Romulan Birds of Prey for my star trek RPG game that I'm building, so yeah, of course that takes up a lot of space, or you may say, of course that takes up a lot of space, so let's rm -fr that bad boy.

Magic words to remember:

du -s | sort -n

Answer 3

KDirStat is another option which will help you identify large files and directories.

I've used the Windows clone WinDirStat a lot and it is an awesome tool.

Answer 4

Check out the Disk Usage Analyzer, you can find it in Programs -> Accessories, it will analyze the disk usage and show it as a diagram to you.

Also, remove unnecessary programs and clear out the old package cache by running sudo apt-get clean .

Answer 5

To expand on Bobby's last point, run:

sudo apt-get autoremove
sudo apt-get autoclean

…to clear out all extra packages and unneeded install files. Also, it would be a really good idea to go through your applications and remove the ones you don’t use any more.

Answer 6

Per the "Linux Server Hacks" by O'Reilly

alias ducks='du -cks * | sort -rn | head -11'

Then go to any directory and run the alias

Answer 7

Software built-in: Disk Usage Analyzer. Fig. 1 Polar coordinate view of masi's /, Fig. 2 Rectangular view of masi's / where you move your mouse to visualize contents

Delete things which you do not need then

1. manually after inspection carefully

2. clean packages in apt-get

   # http://superuser.com/a/113904/2005
   su 
   apt-get autoclean
   

   • Example output in my Asus Zenbook UX303UA where I use the Linux kernel backports (currently 4.6)

     root@masi:/home/masi# apt-get autoclean
     Reading package lists... Done
     Building dependency tree       
     Reading state information... Done
     Del chromium 53.0.2785.89-1~deb8u1 [42.0 MB]
     Del chromium 52.0.2743.116-1~deb8u1 [41.3 MB]
     Del libtomcat7-java 7.0.56-3+deb8u3 [3,623 kB]
     Del mysql-common 5.5.50-0+deb8u1 [81.8 kB]
     Del libmysqlclient18 5.5.50-0+deb8u1 [675 kB]
     Del libservlet3.0-java 7.0.56-3+deb8u3 [314 kB]
     Del linux-libc-dev 3.16.7-ckt25-2+deb8u3 [1,025 kB]
     

3. Remove unused packages if you do not have dependency problems

   apt-get autoremove      
   

4. ...

There are also tools which try to find duplicate files in your system

• use merge and diff tools too to find duplicates in directories
• fdupes, however, can delete wrong files so I am not using it anymore
• ...

If you have an updated working tree and you want to replace an old one in your other system

1. Use rsync by knowing your case precisely because it is sharp - can be efficient or work against you if you do not know what you are doing

   • To rsync -rtvuc in Two Filesystems?
   • ...

OS: Debian 8.5
Window manager: Gnome 3.14