There are few tasks that PSA adds to the cron jobs scheduled in your server operating system:
Statistics counting routine
/usr/local/psa/admin/sbin/statistics is executed every day at 4:07 a.m.
Statistics counting routine counts the traffic used during the previous day and disk space at the current moment and transfers these values into system database. With great amount of domains/logs this procedure will take a significant time.
The traffic usage history is kept for the last 92 days (default setting), and the data on disk space usage is updated every day.
The system database backup
/usr/local/psa/bin/mysqldump.sh is executed everyday at 5:14 a.m.
This utility performs sytem database backing up. Database dump is stored in /usr/local/psa/var/ Further these files are not used in PSA anyhow and are destined for the manual system restoration after failure.
System time synchronization with ntp-server.
/usr/sbin/ntpdate is executed every single hour on the 47-th minute.
This line appears in the crontab after that the admin runs system time synchronization with ntp-server.
The first and the second cron jobs are inscribed during PSA installation, and they can be altered later, all the alterations will be valid at least until a patch installation or a version upgrade.
Cron job execution frequency alteration.
In order to be able to make alterations into the cron jobs it's necessary to use the crontab command.
It's necessary to keep in mind that during cron job execution the time span before the execution should be the least possible, to avoid the possibility of rerunning the cron job until the one previously running has been finished.