--- title: "Linux: how to limit /var/log folder size" category: linux-lifehacks filename: linux-how-to-limit-var-log-size date: 2022-06-16 --- Sometimes the `/var/log` folder grows so large that it causes a shortage of disk space. How to limit the size of this folder? By following the two steps in this article, you can control the size of the `/var/log` folder. ### Step 1. Limiting the size of journald logs The logs of all systemd services are added to the `/var/log/journal/` folder by the `journald` service. To set the size limit for this folder, run the following commands: ```bash sudo bash -c 'echo "SystemMaxUse=100M" >> /etc/systemd/journald.conf' sudo systemctl restart systemd-journald ``` Instead of the `100M` size, you can specify any other size, in `K, M, G, T` units. After the above commands, you can verify that the size of the folder `/var/log` has become the specified size using the command: ```bash du -sh /var/log/journal/ ``` ### Step 2. Limiting the number of log files stored by logrotate Logrotate rotates almost all log files in the `/var/log` folder every day. For example, if I type the command `ls /var/log/kern*`, then I will see that in addition to the file `/var/log/kern.log` I have 4 more files stored that logrotate saved: ```bash ls /var/log/kern* ``` ``` /var/log/kern.log /var/log/kern.log.2.gz /var/log/kern.log.4.gz /var/log/kern.log.1 /var/log/kern.log.3.gz ``` To limit the number of log files, edit the file `/etc/logrotate.d/rsyslog`. Looking at the contents of the `/etc/logrotate.d/rsyslog` file, we can see that the default value of the `rotate` parameter is `4`: ```bash cat /etc/logrotate.d/rsyslog ``` ``` /var/log/syslog /var/log/mail.info /var/log/mail.warn /var/log/mail.err /var/log/mail.log /var/log/daemon.log /var/log/kern.log /var/log/auth.log /var/log/user.log /var/log/lpr.log /var/log/cron.log /var/log/debug /var/log/messages { rotate 4 weekly missingok notifempty compress delaycompress sharedscripts postrotate /usr/lib/rsyslog/rsyslog-rotate endscript } ``` You can change `4` to some other value, such as `1`, so that only one file is stored. In the `/etc/logrotate.d/` folder you will also find many other configuration files related to other log files, where you can also change the `rotate` setting.