trouble booting from external scsi cdrom
 

This is not directly Linux-related, but I /was/ trying to run a LiveCD when this problem popped up.

I have a Crystal CS500 server (P2-400) with onboard SCSI (Adaptec AIC-7880 Ultra3) and an IDE harddrive. The case is a rackmount job so the only internal drive bay is occupied by a 3-1/2" floppy. However, I have a Sun external SCSI enclosure containing a Toshiba CDROM. I thought maybe I could connect the external drive to the server and play around with and/or install Linux (the internal HD has a broken install of Win98 that doesn't boot beyond a DOS prompt).

I hooked everything up this afternoon and put a Damn Small CD in the drive. I went into the regular BIOS and set the boot device order to "Floppy", "SCSI", and "Primary IDE". I assumed it would find the SCSI CDROM and boot as it would from an internal CDROM. During boot I get a message indicating the SCSI adapter was found, then a message identifying the CDROM. The CD spins briefly and then I get a message something like "No SCSI boot device found" and then "No SCSI BIOS found" (I read that this message is normal if not booting from SCSI). The boot process continues normally after that point.

The SCSI ID of the drive is set to 6. I tried changing the SCSI ID to 0 and then 1, hoping the PC was just expecting to boot from a drive with one of those IDs, but that did not work. I put in a Tomsrtbt floppy, booted that, and dmesg showed that tomsrtbt found the adapter and CDROM. From the prompt I was able to mount the CD as /dev/scd0, just like an internal drive.

Any clues? I put the jumper across the pins on the CDROM for "term on/off" which I assumed turned termination on. There are other pins for 'parity' and 'PRV/ALW', but I wouldn't expect these to be necessary since the CDROM works fine except as a boot device. (I am relatively new to messing around with SCSI, forgive me if that's a dumb question.)

If nothing else, is there a boot disk I can use to boot from the CDROM? After installing an operating system I will probably not use the CDROM with this machine, so I really need to do this just one time.

Just because the BIOS has the option to boot from "SCSI" does not mean every SCSI device can be used for booting. Sometimes it is only a hard drive with a SCSI ID of 0 (zero) or maybe 1 (one). Sometimes the device needs to be 0 or 1, depends on the BIOS and/or the firmware on the SCSI adapter.