SCSI vs. IDE detection

[Paul Jimenez]

On Tuesday, Mar 23, 2004, Justin Beckley writes:
>Hello Everyone,
>
>I have just gotten started with FAI.  We are going to be using to 
>install many different types of machines.  Some of these machines have 
>SCSI drives and some have IDE only.  Right now I have an installation 
>that works for one type of drives, but not the other.  I can easily 
>change which type of drive it is and that fixes the problem, but that is 
>a hassle.  I would like to know if anyone has found a good way to let 
>the system decide if it is SCSI or IDE, and based on that decision 
>figure out which drives to partition?
>
>Justin Beckley

I look in proc. My /far/fai/config/class dir contains a a file
'06diskdetect' that's executable and looks like this:

#! /bin/sh
# default to HDA if no one overrides us
disk="HDA"

# if there's a pdc202xx detected, we should use it
if [ -e /proc/ide/pdc202xx ]; then
    disk="HDE"
fi
# are any SCSI devices attached?
if grep -q "^Attached devices: none" /proc/scsi/scsi; then
    :
else
    disk="SCSI"
    # we want also get the filename in front of each 
    # line. So do not use cat, use grep
    [ "$verbose" ] && cat /proc/scsi/scsi
    [ "$debug" ] && grep -H . /proc/scsi/*/*
fi

echo $disk 
# we always want to be able to boot
echo BOOT 
echo MBR 
echo GRUB