Why is disc acces light is permanently on?

Yesterday I realised that the disk access light on my computer was on all the time. There is no flickering at all. Looking at performance with Task Manager the disk showed no activity at all. Watching for a bit there was a very small blip of (low volume) activity once in a while but basically nothing showed.

I am concerned that something is wrong but have no idea just what that might be, nor how to tackle the problem. The computer has a raid setup with the main disk mirrored. My understanding is that if a disk had become corrupted and a process was underway to bring the system to par again, the disk activity would be expected to show on Task Manager.

Any views on what is happening and whether this is as important as I fear would be very welcome!

Thanks

OK, thanks for that reassurance. The light has gone off as suddenly as it came on so that may be all over.

Thanks.

Isn't there an Event log that records disk activity?