Nowadays, most RAID controllers come with a RAID Configuration application and within this application, alerts can be setup.
Check your RAID application, or install one if available. ie: IBM ServerRAID.
You could also use RTMT, realTimeMonitoringTool or Windows Performance Monitor to send alerts.
(RTMT can send email alerts and PerfMon can send network messages or other alert types)
Please see the following link for more info on RTMT Alert configuration:
http://www.cisco.com/en/US/docs/voice_ip_comm/cucm/service/5_1_3/ccmsrva/sartmtal.html