[comp.os.minix] MINIX/ST Using only 4 partitions.

hcj@lzaz.ATT.COM (HC Johnson) (11/11/88)

re: the problem of supporting a small root image on MINIX/ST.

What I did was change the driver, and steal the minor number 6.

After minor numbers 0-5 are set up from the boot block,
I create minor 6, by letting it reference the last 512 blocks of 
partition 3. (And, of course, reduce the size of partition 3 by 512.)

Now I can boot from 3,6 , and mount 3,3 as /usr.

The reason for taking the back 512 blocks is that I first loaded
3,3 with /usr in order to make the change.

Remember to use the -t in mkfs for the root, i.e.
mkfs -t /dev/hd6 512  (any number will do, just remember only 512 blocks
		       are real)

I also changed fsmain, so it automatically tries 3,6 for the root,
and if it fails then tries 2,0 and 3,3.

ALSO, I am using a BMS 100, and having no problems at all.

Howard C. Johnson
ATT Bell Labs
...lzaz!hcj

wheels@mks.UUCP (Gerry Wheeler) (11/14/88)

In article <265@lzaz.ATT.COM>, hcj@lzaz.ATT.COM (HC Johnson) writes:
> ALSO, I am using a BMS 100, and having no problems at all.

Agreed! My BMS 100 controller has worked flawlessly with MINIX. 

I had to pull one little trick to set things up as I wanted.  I have two
Seagate ST-225's, and I want to use one for TOS, and the other for
MINIX. 

I first recompiled the system so MINIX would understand about the second
drive.  No problems there.  The problem was that I wanted a 1 meg
partition for the root, and the rest (19 megs) to mount on /usr.  But,
the Berkeley partitioning program won't allow a partition larger than 16
megs.  At least, it won't if you try to dial your partition size from
the dialog box.  However, if you add a line to bmsinit.dat to add a new
default partition scheme, you can have a 1-19 set of partitions.  I
haven't been able to look at the partition table to be sure it was
written correctly, but so far so good. 

So, I now have two 10 meg TOS partitions on one drive, and a 19 meg
MINIX /usr partition on the other.  I think I died and went to heaven. 

Now to apply all these fixes and new programs people have been posting.
Thanks to you all.
-- 
     Gerry Wheeler                           Phone: (519)884-2251
Mortice Kern Systems Inc.               UUCP: uunet!watmath!mks!wheels
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