Well I'm geting there slowly but surely. This home-built server machine is using hard drive caddies. I've taken my working backup drive from the caddy (secondary master), and replaced it with a small GB test drive. The problem was originally with the drive connected to the onboard IDE primary channel being intermittently autodetected at boot time. I have now swopped the IDE ribbon cables, so the cable that was connected to the primary IDE channel is now plugged into the secondary channel onboard IDE socket, and vice versa for the secondary ribbon cable. Now when I reboot the machine the problem of drives not being detected now appears on the secondary channel, and the ATA drive and CD/DVD-ROM drive are detected OK on the primary channel. I have also replaced the IDE ribbon cable for the channel that was originally connected as primary. So it appears the onboard IDE controller is working OK, and the problem appears to be from the IDE ribbon cable, to one of the HDD caddies. Any suggs please? Kind Regards, Keith Roberts -- In theory, theory and practice are the same; in practice they are not. This email was sent from my laptop with Centos 5.5