(This question deals with a similar issue, but it talks about a rotated log file.)

Today I got a system message regarding very low /var space.

As usual I executed the commands in the line of sudo apt-get clean which improved the scenario only slightly. Then I deleted the rotated log files which again provided very little improvement.

Upon examination I find that some log files in the /var/log has grown up to be very huge ones. To be specific, ls -lSh /var/log gives,

total 28G
-rw-r----- 1 syslog            adm      14G Aug 23 21:56 kern.log
-rw-r----- 1 syslog            adm      14G Aug 23 21:56 syslog
-rw-rw-r-- 1 root              utmp    390K Aug 23 21:47 wtmp
-rw-r--r-- 1 root              root    287K Aug 23 21:42 dpkg.log
-rw-rw-r-- 1 root              utmp    287K Aug 23 20:43 lastlog

As we can see, the first two are the offending ones. I am mildly surprised why such large files have not been rotated.

So, what should I do? Simply delete these files and then reboot? Or go for some more prudent steps?

I am using Ubuntu 14.04.