I don't think my new thread was accepted, so I repeat myself:
I propose to use the Romtec Trios Multi IDE Hard Drive Selector to permit me to boot from a Linux drive or a Windows drive. The drive not in use is disconnected. However, there is a SCSI RAID 5 set of drives connected all of the time. When I boot Linux, I do not want the SCSI drives to be accessible, so that if I goof, and if an intruder seizes control of my system he cannot get to them either. I plan to use the CD-RW drive when I need to move something from one system to the other. Is this plan feasible, and if so, for what must I watch out?
clmilton@charm.net

Ive done this with one box, but I havent pentested it yet to see how hard it would be to regain full access. These three steps I took are purely defensive, and could/could not work for you.

To make it a little bit harder to see what's there you to edit /etc/fstab and delete any corresponding drive entries.
Delete the corresponding scsi drive devices in /proc. Then an intruder would need to make devices himself for which root is necessary (mkdev).
Check if there's no automounter/autosetup kinda daemon running thatll detect/make hw changes.

As an active step to harden your box you could compile your kernel with the GRSecurity patch, which enhances the kernel with a lot of detection features, acl's, restrictions and extended logging, and deploy Snort(+Aide/Tripwire/orr Samhain) as a form of IDS/integrity detection to warn you for anomalies.

HTH somehow

Your thoughtful reply is greatly appreciated.
From reading other threads I see that it was no exception!