Add new harddisk on the fly

So you have this linux box and you want to add an extra harddrive without having to reboot it. The key command we’re looking for, is a way to rescan the scsi bus. This can be achived by rewriting some values in the /sys synthetic filesystem:

echo "- - -" > /sys/class/scsi_host/host#/scan

Replace the digit for the scsi host as appropiate.

If everything went well, you should get output on the console indicating it detected a new hard drive.