Monthly Archives: September 2015

Get the light to flash on an external drive

If you have multiple external drives connected and you need to know which one’s which you can use either of these commands to get it to flash the activity light.

The reason I needed to do this was because I have 3 external usb drives configured as a raid 5. No hot spare so if I see drive error’s they need to be addressed immediately.

X = the drive letter in question.

for i in {1..5}; do hdparm -tT /dev/sdX; done


for i in {1..10}; do dd if=/dev/sdX of=/dev/null bs=10M count=20; done