Posted here as if it can be done it would be a very useful feature.

 

My google foo is failing me... anyone know how to directly flash a HDD LED or if it is even possible. As drive count goes up i would like to be able to see which slot a drive is in.

You could just read the drive with dd for a certain number of blocks.

 

dd if=/dev/md? of=/dev/null bs=1024k count=100000

 

Yeah i pondered that. Was hoping there was a way to just control the LED without drive spinning etc. If thats the only way I think it would be a valuable feature. We would need to experiment to see if we could get a flash pattern though so it stood out.

Not sure if this is even possible on some hardware.

 

I know for sure that on my original IDE based MD1200 assembled and delivered by Lime-Tech, with the originally specified docking trays, that BOTH disk lights on the same cable flashed when EITHER disk was accessed. 

 

This probably was a limitation of the docking trays, but I know for sure there is no way for only one disk light to flash on my system, even if you could command it to turn on somehow. 

 

It is probably justified to power off one day when the server is otherwise idle and label the drives with the model/serial numbers. 

 

Joe L.

 

Here is something that will flash and beep a pattern if your telnet supports the bell character.

 

#!/bin/bash 

export SKIP=0

for i in 1 2 3 4 5 6 7 8
do
    echo -e "Reading ${1}\007"
    dd if=$1 of=/dev/null bs=1025K count=10   skip=${SKIP}
    sleep 1
    ((SKIP=SKIP+1000))

    echo -e "Reading ${1}\007"
    dd if=$1 of=/dev/null bs=1025K count=10   skip=${SKIP}
    sleep 1
    ((SKIP=SKIP+1000))

    echo -e "Reading ${1}\007"
    dd if=$1 of=/dev/null bs=1025K count=100  skip=${SKIP} 
    sleep 1
    ((SKIP=SKIP+10000))
done

Not sure if this is even possible on some hardware.

 

I know for sure that on my original IDE based MD1200 assembled and delivered by Lime-Tech, with the originally specified docking trays, that BOTH disk lights on the same cable flashed when EITHER disk was accessed. 

 

This is a limitation if your drives share an IDE channel.

(A bad practice in a raid array).

 

When I used IDE drives in a raid array I would usually buy extra controllers so that each drive was on it's own channel.

In the past I've had issues where one drive could take down the whole channel, thereby hurting the whole array.

 

This is a design issue that people need to be aware of.

I created an excel spreadsheet, the top couple of rows are shown in the shot below.

 

 

The far left is a representation of how the drives are installed in the case.

 

If ever I need to know where a drive is installed, or which drives are connected to which controler, I can tell easily without having to open up the box.