I think you have no need for troubleshooting in here, if CPU is usage is about 50%. CPU is not causing any slowliness for your storage in those values. If CPU usage is more than 90% for individual CPU, then you might want to take a closer look what is causing it. you can also check >sysstat -x 1 and see if there is some network / protocol load, or disk read/write operations for the system, which could be the reason for the cpu load.
Do you know what is the limit to trigger the alert? Do you get these alerts randomly during a week, or is it happening cyclic?
I would also check the statit command output, it will also show you some cpu and disk statistics and more. It is going to be Average, so 30-60s is enough. This is a good way to gather some performance statistics if you have problem on. >priv set advanced >statit -b wait.... >statit -e >priv set