How can Hardware Monitor warn me when a RAID set or S.M.A.R.T. drive is failing?

This can be done in two simple steps:

  1. Open the pane Probes in the Preferences window of Hardware Monitor and create a RAID or S.M.A.R.T. probe for the drive in question.
  2. Go to the pane Alerts, use the + button next to the table of sensors to be monitored and drag the newly created probe entry from the child window into the table. Make sure the entry is still selected, remove the checkmark at Trigger alarm: When value exceeds threshold of, and set a checkmark at Trigger alarm: When value falls below, entering a value of 1.

You can then select which of the possible alert actions should be taken. If you want to continuously monitor drives, it is recommended to add Hardware Monitor to your list of login items.

Further information: Defining Artificial Operating System Sensors