Logrotate is a system utility that manages the automatic rotation and compression of log files.

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logrotate --version
man logrotate

Configuration can be found generally in two places:

  • /etc/logrotate.conf: contain some default settings, sets up rotation for a few logs that are not owned by any system packages. Also uses an include statement to pull in configuration from any file from the logrotate directory.
  • /etc/logrotate.d: files for packages.

By default, logrotate.confwill configure weekly log rotations, with log files owned by the root user and the syslog group., with four log files being retained at a time (rotate 4) and new empty log files being created after the current one is rotated (create).

Example:

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/var/log/apt/term.log {
  rotate 12
  monthly
  compress
  missingok
  notifempty
}

/var/log/apt/history.log {
  rotate 12
  monthly
  compress
  missingok
  notifempty
}

Any settings in a logrotate file under /etc/logrotate.d will override logrotate’s default values.

  • rotate 12: keep twelve old log files.
  • monthly: rotate once a month.
  • compress: compress the rotated files. This uses gzip by default and results in files ending .gz. The compression command can be changed using compresscmd option.
  • missingok: don’t write an error message if the log file is missing.
  • notifempty: don’t rotate the log file if it is empty.
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sudo logrotate /etc/logrotate.conf --debug

If we declare a logrotate file outside the default directory, we do need to specify a state file. The state file is stored in /var/lib/logrotate/status ; It keep records what logrotate found and if any actions it took the last time it ran.

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logrotate /home/loki/logrotate.conf --state /home/loki/logrotate-state --verbose

If we want to force logrotate to rotate the the log file:

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logrotate /home/loki/logrotate.conf --state /home/loki/logrotate-state --verbose

Finally, we need to set up a cron job to run Logrotate every hour:

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crontab -e