Sooner or later, you will be faced with having to replace a
failed SCO Unix server or updating to a newer server. Hopefully the
latter. I have outlined some of the procedures I used (with the aid
of article in this forum) to replace our SCO 5,05 running Adaptec
alad, 128m 350 mhz server to a brand new Athlon 1.83 GHz server
with 512K memory, Adaptec 29160 controller, and 18 gig LVD
The first problem encountered is the Intel system board and
Intel P4 processor. The new system simply would not boot from
floppy or CD Rom. After many hours of frustration, and with the aid
of the SCO newsgroup personnel (Thanks Bela Lubkin), it was
determined that Intel has decided to enforce the Boot string
requirements. Also after reviewing some other posts in the
newsgroups, it was also noted that version 5.05 does not run very
well on a P4 processor. I decided to just replace the system board
and use an Athlon processor. I got a MSI board and Athlon 1.83 Mhz
processor. To use the Intel, it would have been necessary to
upgrade to version 5.07.
The next step is to load the base OS from floppy and CDROM,
hopefully you have the keys and software. This can always be a
major problem in that usually these systems have been running for
years, and this information is not available.
It is possible to get the information from SCO, but you will at
least need your purchase invoice, and the Serial number.
I purchased an Adaptec 19160 SCSI adapter, because the hard
drive was a U160 LVD. The next problem is that that particular
model does not support SCO, and I had to trade for the 29160 model
which did. This is really strange in that one of these does not
support Windows NT and vice versa. So you have to be careful in
getting the proper card.
Installed the card and drive, added the SCSI CDROM and proceeded
to install the base operating system. The next step is to install
the Tape Drive.
All this stuff is backwards compatible, right. It pretty much
has been, and I never have had any problems before. But this
particular card simply would not recognize the Tape Drive. So I had
to find an older PCI SCSI card from one of my other systems.
The very first and most important step is to get a backup of the
old system. I use CPIO and have for years. It works much easier if
you use separate tapes for each your file systems. Backup /stand
and / on one tape, /u on another, and in my case /hd4 on
Of course if you have the luxury of having both machines
offline, there are several other options like installing the old
drive in new machine, or using DD with CPIO piped to simply copy
the files over a network. These procedures apply to doing this
remotely or when the existing machine cannot be taken offline.
1. Backup the old system with cpio
2. Install base operating system on the new system, and apply
the new driver.
Use the Option to execute divvy so that you can size your
partitions. I expanded my swap, made the / and /u filesystem
larger, and allocated the rest to /hd4. Run mkdev tape to install
the tape unit.
3. Make an boot floppy and root filesystem. Make sure they work.
Probably good idea to make two sets
NOTE: I wasted a lot of time trying to install the driver with
an emergency boot floppy from the old system. The Adaptec driver
would load up, and then abort because of not enough memory. So it
is imperative to get a base OS running from the install disks.
4. Boot with emergency floppy from the new system.
mount /dev/hd0root /mnt
rm -r * // get rid of cur system
cpio // restore the old system
cd / // save boot stuff
mount /dev/boot /b
cp -r /b /mnt/bootstand
mount /dev/boot /mnt
rm -r *
cpio // restore /stand
mount /dev/u /mnt
rm -r *
cpio // restore /u
mount /dev/hd4 /mnt
rm -r *
cpio // restore /hd4
5. Chroot to hard drive
mount /dev/hd0root /rootmount
chroot /rootmount /bin/sh // see man chroot
That lets you install the driver, but hasn't told the system to
USE that driver.
Identify the current disk driver by
grep Sdsk /etc/conf/cf.d/mscsi
Your current driver will in column 2- examples "alad", "arad",
Identify what driver you need by examining /etc/default/scsihas
(if you used a btld, it's whatever you installed)
Edit the current driver file and change the "Y"'s to "N" in the
first column. For example, if your current driver is alad, you edit
/etc/conf/sdevice.d/alad. Edit the NEW driver file and change "N"
to Y. Example, your new driver is "blad", you edit
Next, cd /etc/conf/cf.d and edit mscsi. Change the driver column
to match your NEW controller. For example, changing from alad to
blad with vi:
The following gave me a warning so I just made a copy of /stand
early in process.
cp /stand/unix /stand/unix.good
Everything linked but did not get the chance to install as
cp unix /stand
and reboot from harddisk, TCP will fail because of the drivers
for your netcard, The video and mouse will have to be
I also got the INCORRECT ISAM version error. Simple fix is to
execute isverify from a root prompt.
The system was shipped to the remote location for the final
test. The old machine was removed, and replaced with the new
server. System was powered on, and Everything Works.