Adding a second hard drive SCO Xenix, Open Desktop, Openserver
This article references SCO SCO Xenix, Open Desktop, Openserver specifically. See Linux/adddrive.html for adding a Linux drive.
You add a hard drive, and configure the file systems on it, by
running "mkdev hd".
People used to older Unices may expect more complications, and
may expect to have to use "mkfs" after hand editing kernel
configuration files to add the appropriate block and character
devices. You certainly can do all that if you want, but "mkdev hd"
is a front end that makes it much easier. If you are curious as to
what goes on behind the scenes, look in /usr/lib/mkdev. The "hd"
command there is a shell script, and is fairly
You generally have to run 'mkdev hd' twice. If I remember
correctly, the kernel already has the code for the second IDE
drives, so in that case it's only once. But for SCSI drives, the
first invocation puts the driver code in, and the second (after a
reboot) allows the partitioning and division of the drive.
For SCSI drives, the first pass asks you the name of the SCSI
controller. If you don't know, and if your primary drive already is
SCSI, look in /etc/conf/cf.d/mscsi. The end of the file might look
wd Srom 1 0 0 0
asc Sdsk 0 0 0 0
asc Sdsk 0 4 0 0
(This happens to be a machine with an EIDE cdrom and a scsi disk
using an "asc" controller, plus a second scsi disk at ID 4). You'll
also be asked about which controller (if you have only one, it's
"0"), what bus (probably 0) and the target ID. and the lun (almost
There are twin-channel controllers: for these, one is controller
"0", the other is "1". You can follow the internal cables to see
which one your drive is connected to.
If you aren't sure what SCSI devices are present,
the "sconf" command can help you on modern systems. Prior to
OSR5.0.5, this existed but could crash your system in multiuser
mode, but now is safe. Here's the output of "sconf -v" on one of my
Sdsk alad 0 0 0 0
Sdsk alad 0 0 1 0
Stp alad 0 0 3 0
Sdsk alad 0 0 4 0
Srom alad 0 0 6 0
For example, this tells me that a tape drive (the Stp line) is
attached to an alad controller, and (reading left to right), it's
alad unit 0, on bus 0, at id 3 and lun 0.
After answering these questions, the kernel is relinked. Be sure
to answer "Y" to "Rebuild the Kernel Environment", and be sure you
understand what that question means (if you don't, make a copy of
/etc/inittab before you begin this process). You do have to reboot
before proceeding to the next step. You then run 'mkdev hd' again,
and answer the same questions.
If you got it wrong:
If you guessed wrong about the controller, bus, or ID, you won't
get the screens that ask about the partitions. If that's the case,
don't use mkdev hd, simply go directly to /etc/conf/cf.d/mscsi,
make the corrections, and link a new kernel. The controller is the
first column after Sdsk, the ID is the second, then lun and bus.
Simply change the appropriate column, and then relink.
If you don't feel comfortable with that, at least vi mscsi to
remove the line that represents the error. Once you've got that
correct, 'mkdev hd' will proceed to the second phase, where you
create the Unix partition and then divide it into one or more
During that second phase, you are asked if you want "block by
block control". If you answer that affirmatively, you get to
control everything about the division(s) created, including the
If you have existing data
You may want to transfer an existing disk to another system, as
for an upgrade. The procedure is the same, but do NOT change the
partition info, do NOT change the bad track table, and do NOT
create new filesystems. You'll see your divisions; all you need to
do is (n)ame them and proceed from there.
If you don't, an arbitrary (e.g. "d1150" ) name is generated.
It's not actually completely arbitrary: it is related to the drive
number and its id if scsi. I think it's been documented somewhere,
but I never pay attention to it because:
- You can name the divisions sensibly
- You can always find out what someone else named them
The "finding out" can be accomplished by using 'divvy' on the
appropriate device. "man HW hd" gives tables of drive names, and
from that it's easy to find out /dev/hd1a will represent the second
physical disk. Therefor, 'divvy -P -N /dev/hd1a' will print out
info about the divisions, including the names.
Or, you can use divvy interactively, leaving out the -N and -P.
By doing this, you can even change the name to something more
sensible. I like to use names that are reminiscent of the mount
points, so my Jaz drive has a division 'jaz', which creates a
/dev/jaz, which I mount at /jaz.
Note here that the second pass of "mkdev hd" will have invoked
divvy for you: you don't need these commands unless you need to get
back to the divvy tables after this. Note also that if you already
know the name of the division (such as /dev/u), you can get there
with "divvy /dev/u"
You may want to creat multiple partitions. See Adding disk space for
The final step, of course, is to do the mount. You can manually
edit /etc/default/filesys ('man filesys'), or you can use 'mkdev
fs'. This does NOTHING TO EXISTING DATA. It only creates
/lost+found and adds the drive to /etc/default/filesys. You can
safely use this with any drive.
You didn't pay attention to the name of the division and didn't
change it from the default? Look at the "Existing Data" section
just above this.
For some reason, there is no mention of 'fs' in the man page for
'mkdev', but it's been in /usr/lib/mkdev for a very long time. It
asks the appropriate questions, and if you give it appropriate
answers, it will create the appropriate entry in
You get asked for the device name. Answer that with the name of
the division. You are then asked for a mount point, and finally you
are asked if you want to always mount this filesystem. Generally,
you'll answer yes to that.
If you told it to "always mount", you can then mount it by any
of "mountall", "mount /mount_point", or by rebooting.
For ideas about what to do with this extra space see Adding disk space.
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