If you find the Adaptec 2940AU doesn't see devices during a warm boot
then try turning on the SCAM in the SCSIselect bios.
I saw this on another group and tried it. I don't know why but it
worked for me. :-)
Has anyone tried using an Adaptec 2940AU controller with a SyJet as
the boot device? If there is only one device on the internal cable
it goes through the motions of booting up to the point of loading
the kernel, detecting the devices, reading the partitions, then
it gets a disk error and can't mount the root device. Adding a
2nd SyJet on the external connector makes it work with no other
changes. I don't think this is related to termination since adding
a cable with a terminator to the external connector doesn't help.
This machine is being set up for development/testing and will normally
have both drives connected but I'd like to know what is going on.