Question : How to tell if a RAID array fails

I have come across a "server" running XP Pro that has 2 SATA drives in a RAID 1 array that uses the motherboard's RAID controller.

I don't really have any experience with RAID arrays - so I have a couple of questions.

This box is headless and nobody checks on it daily.  It does run a VM of 2003 Server Enterprise which acts as a file serve for apps running on the client machines in the office.

My question is how would we tell if the RAID array fails?  If I understand it correctly, a RAID is supposed to keep things running in the event of a drive failure.  If it does that, wouldn't it just keep going without alerting us to the failed drive?

If the machine failed to load the OS on a restart until a function key was pressed to acknowledge a drive failure, at least we'd know there was something wrong before the second drive failed and we were SOL.

The RAID software does not email anyone or pop up a warning on another machine to my knowledge.  

So, what's the deal?  What happens when one of our drives fails in the 2 drive RAID 1 array?  

Answer : How to tell if a RAID array fails

Not all RAID arrays offer redundancy, but a RAID 1 does.  RAID one is often called a mirror because it does just that; it mirrors the data in case on of the 2 drives fails.  If the array is actually built on a RAID controller (not a windows software mirror), then the RAID controller should sound an alarm in the event that the array is degraded.  If the array is degraded (1 disk fails) then the system will sound the alarm (audible annoying beeping) and continue to run.  If the disks are hot swappable, you can replace the failed disk while the system is running, then rebuild the array from your array management software (i.e. Adaptec Storage Manager).

Here is a link to an article that explains the different types of arrays:

http://www.hardwareanalysis.com/content/topic/67628/