Before you begin, ensure that you are logged in to the terminal as the root user.
1.Check the disk space from the command line. Use the du command to see which files and directories consume the most space inside of the /var/log directory.
#du -h /var/log/
The du command prints the estimated disk space usage of each file and directory for the path that you specified.
The -h argument causes the command to print the information in a human-readable format.
The output of the du command :
root@host [~]# du -h /var/log/
24K /var/log/cups
16K /var/log/mail
36K /var/log/prelink
19M /var/log/audit
84K /var/log/bandwidth/2011/Jun
128K /var/log/bandwidth/2011/Jan
116K /var/log/bandwidth/2011/Feb
712K /var/log/bandwidth/2011
4.5M /var/log/bandwidth
2.6G /var/log/munin
8.0K /var/log/conman.old
8.0K /var/log/pm
8.0K /var/log/conman
12K /var/log/dcpumon/boot.1308161402
5.3M /var/log/dcpumon
8.0K /var/log/vbox
3.7G /var/log/
2.Select the files or directories that you want to clear:
The /var/log/munin directory uses 2.6 G of space, and is the second largest log on the list.
Use the cd command to move the prompt to the /var/log/munin/ directory. Then, use the du -h * command to see the file sizes.
The du -h command, without the asterisk, shows the directory's size:
root@host [~]# cd /var/log/munin/
root@host [/var/log/munin]# du -h *
603M munin-graph.log
385M munin-html.log
67M munin-limits.log
99M munin-node.log
1.5G munin-update.log
The du -h command, without the asterisk, shows only directory's size
root@host [/var/log/munin]# du -h
2.7 G.
3.Empty the files
Use the cat command (concatenate) to empty the log files or directories.
#cat /dev/null > munin-update.log
- /dev/null is a non-existent file with no information.
- When you concatenate /dev/null to a log file, you empty the file data, but do not delete the file name.
The output from the previous example shows that the munin-update.log file occupies 1.5G of space in the drive.
To empty this file, use the cat command.
The output should resemble the following example:
root@host [/var/log/munin]# cat /dev/null > munin-update.log
root@host [/var/log/munin]#
To confirm that you successfully emptied the file, use the du -h * command.
root@host [/var/log/munin]# cat /dev/null > munin-update.log
root@host [/var/log/munin]# du -h *
603M munin-graph.log
385M munin-html.log
67M munin-limits.log
99M munin-node.log
0M munin-update.log