I set up a Panther Server with a few shares, and noticed that I (an admin) could mount all of the volumes from an OS 9 workstation, but only the shares from an OS X workstation. I looked for the OS 9 style "Allow owner to see all disks" but couldn't find it. A call to Apple revealed the solution in the following file:
/Library/Preferences/com.apple.AppleFileServer.plistThe property admin31GetsSp defaults to true. Change it to false, and logging in to the OS X Server from an OS X workstation as a user in the admin group will allow you to mount the root volumes on the machine.
Mac OS X Hints
http://hints.macworld.com/article.php?story=20040416150608275