Custom disk partitions (i.e. > 4)

[Norm Meluch]

	Greetings once again netlanders,

	Currently I am in the process of trying to "customize" the partitioning
on our 386s here at CFC.  The machines I am working with are several (Olivetti)
AT&T 6386 E WGS (20 MHz) machines running AT&T SysV 3.2.1.
	Each came with 1 - 135 MB ESDI (3:1) hard disk and controller.
	I am trying to add a 300 MB ESDI second drive to each machine.

Heres what I know so far:

1)	Not only do you have to buy the 300 MB drive, but a AT&T Suplemental
	Kit.  This "Kit" is a euphamism for 1:1 interleave controller (WD1017).
        Seems my systems were shipped with 3:1 (WD1015) and they don't support
        300 MB drives.
	Fine.  Set delay = 1 month.

2)	Oh yeah.  3.2 has a bug with finding and swapping out bad tracks on
	300 MB disks.  We'll send you "fix #69" (no lie) for that problem.
	This basically makes the OS 3.2.1 ( I think/hope ).
	Set delay = 2 weeks.

3)	I find there are no instructions in Supplemental Kit.  Just a board
	two disks, and a pair of chips.

	Another call to AT&T says, "No you don't need those chips".
	"They're just ROM upgrades for the PC."

	Whew!

	"But wait!  You'll need Low Level format v 2.01.1."

	"Let me guess.  A bug with 300 MB drives?"

	"Yep."

	Set delay = 1 more week.


So, while I'm awaiting those utilities I have been working on creating a plan of
action for the disk installation.

Now, the install of the OS only allows one to create 4 (including swap)
partitions maximum on the first hard disk, and the diskadd (and I use the term
loosely) utility also only allows for the creation of 4 partitions max.
	These partitions correspond to:
/dev/dsk/0s1	/dev/dsk/1s1
/dev/dsk/0s2	/dev/dsk/1s2
/dev/dsk/0s3	/dev/dsk/1s3
/dev/dsk/0s4	/dev/dsk/1s4

	Fine.  However, these 386s are file servers on our network.  Being
such, users have the nasty habit of grabbing all the disk they are permitted to
take, and so 4 partitions on 1 300 MB hard disk don't cut it.  One department
inevitably ends up munching on anothers "space".

	Therefore, I wish to create > 4 partitions on each disk.

	After dissecting the INSTALL script for the Base System (and diskadd)
I have found most of the answers I need to know, but I still have a few
questions that I would feel better about having the answers to.

	Here's the question(s):

1.	Does the # of the partition in /etc/partitions correspond to the "slice"
	number of the device?

usr2:	 partition = 4, start = 310590, size = 312120,
	  	     ^	tag = USR, perm = VALID
		     |
		     v
/usr2     /dev/dsk/0s4

2.	Thus, can I use /dev/dsk/[01]s[789], or are they for alt, reserved, and
	trkalt?

3.	Will the device driver for the hard disk support me creating more
	more /dev/dsk devices without modification?  Seems that since
	/dev/dsk/1s0 = maj 0 min 16, I should be able to have 16 devices for the
	first hard disk on the system.  Yes?

	Hopefully I just mknod, and I'm all set.  Or is there a fix for that
	too?

Any and all answers will be greatly appreciated.

						- Norm

|~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Norman J. Meluch ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~|
| Mail:norm at cfctech.cfc.COM            Fax:(313)948-4975  Voice:(313)948-4809 |
|~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~|
| Note: The opinions expressed here are in no way to be confused with valid   |
|_______ideas or corporate policy.____________________________________________|