[CentOS] how to control Hard Drive light from Linux?

On Sat, Jan 22, 2011 at 5:03 PM, Rudi Ahlers <Rudi at softdux.com> wrote:
> Hi all,
>
> Does anyone know how to control a hard drive light from Linux? I'm
> building a 24bay Linux File server which will run software RAID and I
> need an easy way for the engineers to see which HDD has gone bad.
>
> Most of our NAS devices has 2 lights on the hard drive cages and they
> automatically signal a bad one (reg light, light constant on , etc)
> but I can't figure out how todo this from Linux.
>
> --

This page might help:
http://pikawarp.org/?p=139


Talks about setting entries in /sys/class/leds.