Attaching an external scsi disk drive to an Indigo
By Patrick Wolfe
Last Updated March 15, 1994

1. Step ONE:  connect it up

Make sure you set the scsi id# of the disk to something the system
expects.  It has to be a single digit in the range 0-6.  Most external
cabinets you set it via a switch on the back.  Some ancient disks, you
have to read the drive's manual, and set jumpers on the back of the
disk drive itself.

Your Indigo's system disk is id 1.  If you have no other internal
disks, just choose 2 (the same as the middle internal slot, so don't
use 2 if you have something in there, for example a tape drive or
internal disk drive).

Power the disk up and the system and abort the auto-boot.  Select
'command monitor'.  If you are prompted for a password, then someone
has set the boot rom password.  If you don't know it, you can reset it
by rebooting into multiuser unix, become superuser, and run 'nrvam
passwd_key=""'.  Then shutdown again.

At the prompt, enter 'hinv'.  If you see your new disk, you're done
with this step.  If not, go back, double check your inventory, scsi id,
cabling, etc.

Make sure you don't have too much scsi cable, and check your
terminator.  I've been reading about 'active' terminators solving some
people's scsi problems, but I don't know if that's what sgi ships.
Probably not.

It's probably simple, but you may also have a hardware problem.  The
system HAS to recognize the drive now, or you can't continue.

2. Step TWO:  Format it

If you bought from a reliable vendor, like Falcon or Compuplus (or any
of the other 3,000 that will probably respond to this posting saying
"you didn't mention meeeeee"), you can skip to step two.

Read the manual on this.  It's menu driven, but the booting procedure
is such a pain in the butt, I'm not even going to attempt describing it.

Basically, you will boot standalone 'fx'.  Make sure you specify the
'-x' option.  I think you simply choose 'a' for 'automagically do
everything I want' and then sit back, and tell yourself again how smart
you were for choosing a vendor who made this so damned easy.

Depending on the drive size and speed, it could take hours to finish.

When it's done, if everything worked out, continue.  If you had
excessive errors, you might want to call your drive vendor.  Keep in
mind that for multi-gigabyte drives, a thousand bad spots is really
nothing to worry about.  What's a megabyte among friends?

3.  Step THREE:  Partitions

You'll probably need to create new partitions on your disk.  You do
this in 'fx' too, but you don't have to be in the standalone 'fx'.  If
you're already there, fine.  If you're running Irix already, just
become superuser and run it.  You specify scsi bus zero (the default),
and type the scsi id number of your new disk.

The 'r' repartition menu is fairly easy to do.  You may have to do some
math.  If you're an old hand at repartitioning, just slip into the
'e'xpert mode (only available if you ran 'fx -x'.

Read the documentation.

4.  Step FOUR:  Devices

Bring the system up to multiuser unix and become superuser.

cd to /dev/rdsk and run 'ls'.  You'll see lots of files like
"dks0d6s0".  The numbers in that string mean something.  In the above,
it's 'dks0', which means internal scsi bus number zero.  The following
'd6', means scsi id 6.  The final 's0' means partition number zero.  If
your disk has only one partition, then it'll probably be under slice
zero.

For example, if you added a 2.1 Gb disk as scsi id 2, and wanted the
whole thing in one partition, you'd partition the disk as a 'data'
drive back in step 3 (go back and read that part now if you skipped
ahead).  If you put it all in partition zero, you'd want to check for
device '/dev/rdsk/dks0d2s0'.

It should already exist.  Read the manpage on 'mknod' or read the
comments in the '/dev/MAKEDEV' script.

5.  Step FIVE:  create a filesystem on the disk

You create a filesystem on a disk partition using the 'mkfs' utility.
Run 'mkfs -i /dev/rdsk/dks0d2s0' making sure you get the scsi id
right.  Be careful!  If you run this on a disk with data on it, you can
lose data!

The '-i' option causes a prompt to appear.  Use this opportunity to
make sure you set the scsi id right.  Last Chance before you screw up
something!

6.  Step SIX:  Mount it

Edit /etc/fstab and add a line for each new partition.  For example:

	/dev/dsk/dks0d2s0  /usr2  efs rw,nosuid,nodev 1 1

You would mount it by running:

	mkdir /usr2
	mount /usr2

Fix the permissions in the root directory of the new partition.
It must be mounted to do this.  For example:

	cd /usr2
	chgrp abc .
	chmod g+ws,o-rwx .

7.  Step SEVEN:  Enjoy!

Good Luck!
-- 

	Patrick Wolfe (pwolfe@kai.com)
	Sr. System Manager, Kuck and Associates