Recently my server was giving notifications of disk io activity rising above a certain threshold at regular intervals. My first guess was that some cronjob task was causing that. So I tried to check various cron tasks to find out which task or process was causing the io burst. On servers specially it's always a good practice to monitor resource usage to make sure that websites work fast and well.
However searching manually is not quite easy and this is where utilities like iotop come in. iotop shows what or how much disk io are all current processes doing. Its quite easy to use.
Read more at Binary Tides.