Symptoms

Log rotation settings for a subscription has Maximum number of log files parameter set to 5 in Plesk 12.0. The subscription has 5 log files below:

    access_ssl_log.processed.1.gz
    access_ssl_log.processed.2.gz
    access_ssl_log.processed.3.gz
    access_ssl_log.processed.4.gz
    access_ssl_log.processed.5.gz

After changing the Maximum number of log files parameter to 2 via control panel, Plesk rotates the log files. The result is supposed to be as below:

    access_ssl_log.processed.1.gz
    access_ssl_log.processed.2.gz

However, the following one appears:

    access_ssl_log.processed.1.gz
    access_ssl_log.processed.2.gz
    access_ssl_log.processed.4.gz
    access_ssl_log.processed.5.gz

Cause

This behaviour is by design. When Maximum number of log files is set to 2, it means log files are rotated two times before being removed. So, logrotate cares only about two files.

Resolution

Older files can be removed either manually, or using a script.The script-based solution can be as follows:

1. Create cleanup_old_logs.sh with the following content:

   # Usage: cleanup_old_logs <folder> <days>
   # Removes all log files in the directory older than a certain number of days
   FOLDER=$1
   N_DAYS=$2
   
   # Validate
   if [ "$FOLDER" == "" ] || [ "$N_DAYS" == "" ]
   then
           echo "Usage: $0 folder number_of_days"
           exit 1
   fi
   
   if [ ! -d "$FOLDER" ]
   then
           echo "$FOLDER is not a directory"
           exit 2
   fi
   
   # Remove
   echo "Deleting files in $FOLDER older than $N_DAYS days"
   find $FOLDER/* -mtime +$N_DAYS -exec rm {} \;
   

2. Add the following sample entry to /etc/cron.daily/50plesk-daily to remove all logs older than 15 days:

    cleanup_old_logs.sh /var/www/vhosts/<domain_name>/logs/ 15 >/dev/null 2>&1