Bakup log rotation
Plesk does not rotate backup logs and we needs to delete them by manual.
Backup log might be very big, therefore Plesk should rotate backup logs automatically to prevent oppression of disc capacity by increasing backup logs.
Related KB: http://kb.odin.com/en/113748/
Thank you for your input. We will consider this functionality in upcoming releases, if it will be popular.
Everyone, please continue voting for this feature if you consider it important.