I have number of MySQL databases, I have used tools such as dstat, vmstat I'm just unable to determine when do I need to add more drives to increase performance.
the number of databases are increasiing over months and I have been asked to increase the performance, I have been adding faster drives, but I would like to know if there is an easy way to know if the system for example the number of iops being used is over %80 therefore you need to add more drives .. etc
Thank you