> I am attempting to move a disk running Altos SCO Unix (the Altos version of SCO
> v3.2) to a new Altos 9000 Chassis. When the Operating System was installed I
> used the 'arad' driver disk (AIC 7700 I think) that came with the machine. The
> new Chassis has a backplane that uses the 'alad' driver (AIC 7800 I think).
> Whilst the disk boots in the old machine, the 'no operating system' message
> appears when I try to boot it from the new machine.
> I have booted the new machine from an Emergency Boot & Root Floppy from a SCO V5
> system, but it will not allow me to mount the hard disk file system, reporting
> unrecognised file system (error 22).
> Any suggestions as to upgrading the file system with the new driver would be
> gratefully received. I do not wish to re-install the OS, and rebuild the disk if
> I can avoid it.
Both the "NO OS" message that you get when trying to boot the disk, and
the "unrecognized file system" when you try to access it from an OSR5
boot/root set, indicate disk parameter problems. The partitions on the
disk were created relative to one disk geometry, while the alad driver
is using a different geometry for the disk.
OSR5 has a facility by which the geometry of a SCSI disk can be
overridden. Unfortunately, that facility does not work with older
releases. There is one hope: some of the parts, and perhaps all (I'm
not sure) of that facility are included in uod429a. Can you put the
disk back into the old chassis, boot it, and install uod429a? Once it's
installed, relink, reboot, and then run
dparam /dev/rhd00 `dparam /dev/rhd00`
(you must run this after having rebooted with uod429a in the kernel;
otherwise it will have no effect).
Once that's done, reboot again to verify that the disk is still bootable
in the old machine. Also build an "alad" kernel while you're at it
(edit /etc/conf/sdevice.d/alad, change "N" to "Y", relink). After that,
make a new set of boot/root floppies with `mkdev fd` (this set will be a
3.2v4.2 (or Altos whatever-release) boot/root set with both arad and
alad drivers in the kernel, and with the SCSI disk parameter changing
facility in the kernel). Then move the disk to the new machine with the
2940 controller. Boot with "defbootstr Sdsk=alad(0,0,0)". Any luck?
While you're doing this, be sure to note the disk parameters seen with
the old controller. You want to see the same parameters with the new.
Since you can't boot as long as they're wrong, you won't see them
directly; but you can boot your new boot/root set and try to mount the
hard disk. That will get you at least a "%disk" message with the