I'm trying to get hard disk activity status for each individual disk in my RAID array. Before, when my RAID was based on PATA devices, the ability to get an LED for each individual disk was very easy (involved just tapping off one of the IDE Pins, I think pin 39 and wiring to an LED).
Now I have a sata raid array, and I can't use the method above anymore (as SATA connectors do not have a simple pin for LED activity).
So far the only method I have thought of involves software. I found that windows has a program which can register hdd activity (called hddled) and was wondering if anyone here either knows of a linux program that can do that or can give me tips on how to write one.
Seeing as the linux kernel has to send commands to the disk in order to make it do things I assume that there is some sort of interrupt for this. If anyone has any ideas for how I can do this, please let me know