How to limit log file size in Linux?

To limit log file size in Linux, you can use log rotation. Log rotation is a process that renames or moves a log file and creates a new one when it reaches a certain size or age.

The logrotate command is a built-in tool in most Linux distributions, and it can be used to configure log rotation for specific files or directories. Here’s an example of how to configure log rotation for a specific file:

1. Create a configuration file in the /etc/logrotate.d/ directory:

sudo nano /etc/logrotate.d/example

1. Add the following content to the configuration file:

/var/log/example.log {
    rotate 4
    maxsize 10M
    compress
    delaycompress
    missingok
    notifempty
}

Here, /var/log/example.log is the path to the log file that you want to rotate. The rotate 4 option means to keep up to 4 rotated log files. The maxsize 10M option means to rotate the log file when it reaches 10 MB. The compress option will compress the rotated log files using gzip. The delaycompress option means to compress the rotated log files the next time the log file is rotated. The missingok option means to not raise an error if the log file is missing. The notifempty option means to not rotate the log file if it is empty.

1. Save and close the file.
2. Check the configuration file:

sudo logrotate -d /etc/logrotate.d/example

This will show you what logrotate would do, but it won’t actually rotate the log file.

1. Test the configuration file:

sudo logrotate -f /etc/logrotate.d/example

This will force the logrotate to rotate the log file.

By default, log rotation is usually set up to run daily via a cron job, but you can customize the rotation cycle as well.