(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.