How to delete logs automatically after a certain time and restart the process that fills up the log file?

Server is Ubuntu 16.04. I have a process running with nohup that logs into a local file. This file gets big enough to consume 100% disk space. To resolve this I have to kill the process first and then remove the log file. Then I restart the process. How can I resolve this with a script or some other tool?

3 Answers

With logrotate you can configure how big a log file may get or after how much time:

• the log files are rotated (log.n becoming log.n+1, and the last log file being deleted)

• the current log file is truncated without disturbing the writing process.

Take a look at man 8 logrotate.

I guess that you start the script/program with nohup like

nohup scriptname 1>logfile.log 2>& &

I would recommend instead of deleting the log file just to clear it with

echo -n >logfile.log

If you delete/move an open file it will be written until the process will close the file or the process will end.

To delete all logs automatically, edit the .bashrc file using your favorite text editor. Here I'm using nano. In your terminal run:

nano ~/.bashrc - 

Add the following to the bottom of the file:

rm -r /var/log # Deletes logs directory
clear # Clear the terminal

Press Ctrl+O to save and Ctrl+X to exit edit mode.

The .bashrc file is executed every time you log in or launch a terminal instance, thus your logs will always be deleted.

You can also delete them based on time. E.g. delete all logs created 3 days ago using:

find /yourlog/path -mindepth 1 -mtime +3 -delete

• -mindepth 1 means process all files except the command line arguments.
• -mtime +3 will check for the files that were modified 3 days ago.
• -delete will delete them.