overby@plains.NoDak.edu (Glen Overby) (04/02/91)
[ If you have questions and answers to contribute, please send them to me, ]
[ overby@plains.nodak.edu ]
Commonly Asked Questions on Comp.Os.MINIX
The venerable Minix Information Sheet never seems to satisfy the endless
questions asked on comp.os.minix. It's prose style probably doesn't lend
itself to the quick hand-holding that some seek.
As a result, I have decided to create this "Question-Answer" format compan-
ion to hopefully fill the gap. It's an impossible task, but maybe this
will help.
In creating this, I have attempted to recall the Great Questions (and their
answers) as well as the Great Discussions from the net. Many thanks to
those two people who have contributed to this document.
Several things to remember when you ask questions on the net:
Supply enough information for people to actually help you. Things like
what Minix version, your hardware configuration, and so-on are almost al-
ways necessarey to not have to take shots in the dark. If you are reluc-
tant to tell any or all of this, don't expect a good answer.
1. Where can I get MINIX?
Minix is sold by Prentice-Hall, Inc. and their authorized distributors.
They hold the Copyright on Minix, and sell it for profit (or at least we
assume they make a profit on it).
IT IS NOT AVAILABLE FOR ANONYMOUS FTP!
2. What versions of Minix exist?
The most current version is 1.5.10, known simply as "1.5" if you buy it
from Prentice-Hall. Upgrade "diffs" have been posted to the net over the
past several months; consult an archive site listed in the Info Sheet to
find that. Prentice-Hall has been shipping ALL versions of Minix 1.5 for
several months.
3. But I've heard of this a newer version, 1.6.15.
Yes, that sort of exists; it is a mid-development beta release for the PC
(only) released to beta-testers.
4. PDP 11/44 Memory Management
This was the first big off-the-topic discussion on the group, and it's
still not an appropriate topic, so if you are still intrigued about pdp-11
memory management, consult the DEC processor handbooks, or some harmless
newsgroup like alt.dev.null.
5. Please subscrbe me to the mailing list
why ask 26,000 people to do that, when there is one person who can do it,
and you can ask a computer to do it for you.
If you are on bitnet or arpanet, you can get this newsgroup via a mailing
list, info-minix. To subcribe to the list, send a message to
listserv@vm1.nodak.edu (internet) or listserv@ndsuvm1 (bitnet) saying:
signup minix-l your_full_name
If you have trouble, contact the list maintainer at info-minix-
request@udel.edu.
6. Please Unsubscribe me from the mailing list
Use the same procedure as for subscribing, but use "unsubscribe" instead of
"signup".
7. What is the root password?
It's in the book, on pages 373 (login "ast") and 380 (login "root"). If
you didn't buy the book, that's only the start of your problems.
8. MINIX doesn't work with my hard disk.
There are many potential sources of this. Several are:
You are running an RLL controler. You must change "NR_SECTORS" in the con-
figuration file, <minix/config.h> from 17 (standard for MFM controllers) to
25 (Adaptect controlers) or 26 (Western Digital and others).
9. Is there a SCSI driver for MINIX?
All SCSI controlers work differently, from the primitive Seagate ST01, to
the smarter Always IN-2000, and Adaptec with it's own on-board CPU. Nobody
has yet posted a wini driver for any of these, but there has been talk of
it. For now, you are stuck using the ROM wini driver.
10. The single threaded filesystem is a real bottlenck.
True. It's only noticeable when you are running massive bacground
processes, or putting multiple users on your computer.
You've got the source. Fix it.
11. Is there a 386 Minix?
Minix 1.5.10/PC runs on 80286 and 80386 systems using 80286 protected mode
(so all your memory is used for programs, rather than as bank-switched
memory "windows" or a big RAM disk). There is an experimental 32-bit ker-
nel from Bruce Evans. It is available from sirius.ucs.adelaide.edu.au in
Australia and as plains.nodak.edu.
12. I have an old version of Minix. How can I upgrade?
You need to get an upgrade kit from one of the archive sites; see the Minix
Information Sheet for a (supposedly) complete list of sites which archive
Minix-related bits.
Also, read the Upgrading Tutorial -- it was ment to help.
13. What shells exist for MINIX?
sh: Your typical Bourne shell. Comes with distribution Minix
clam: Tcsh-like shell, runs under Minix & real Unix's. Available
from ftp sites sirius, ccadfa, plains & others
ksh: Korn shell, ported to Minix. Diffs for Minix on plains.
marvin: A kid's shell. Posted months ago in comp.os.minix.
emacs: Does this count as a shell? Works only under 68K-Minix's
and perhaps 386-Minix.
14. Is there X-windows for MINIX?
No, there is not. It would be difficult if not impossible (that was ment
as a challenge!) to put X on Minix because X is huge. Unless you have many
megabytes of memory, it would be impossible to run X clients and servers on
one machine. It will also certainly require 32-bit mode operation.
15. Why can't my PC can't boot PC-MINIX from 1.44Mb floppy disks?
There's a couple of reasons for this. First, straight out of the box,
MINIX doesn't plan on dealing with 1.44Mb floppy disks. The entries in
/dev should be set up specifically for your machine, so pick out the
correct entries here:
mknod /dev/fd0-dsdd5in b 2 4 360 # Drive A, 360K 5.25"
mknod /dev/fd0-dshd5in b 2 8 1200 # Drive A, 1.2M 5.25"
mknod /dev/fd0-dsdd3in b 2 16 720 # Drive A, 720K 3.5"
mknod /dev/fd0-dshd3in b 2 28 1440 # Drive A, 1.44M 3.5"
^^^ ^^
Change 'fd0' to 'fd1' and add 1 to the minor device number to create an en-
try for floppy drive B. It may be a good idea to link the generic floppy
disk entries (/dev/fd0 and /dev/fd1) to the proper /dev/fd0-ds{whatever}
entries for your machine, so that programs like dosread continue to work.
Second reason your PC won't boot from 1.44Mb floppy disks, even though
you've fixed up the floppy disk device entries: tools/bootblok.s doesn't
know about 1.44M disks, so it blindly loads the boot image incorrectly and
then tries to execute it. Get Guy Helmer's bootblok.s from an archive
site, or get shoelace.
16. What's wrong with 'ps'?
You need to have a copy of the compiled kernel in /usr/src/kernel/kernel
for ps to read the namelist out of. Note that this MUST be the SAME kernel
that is booted.
17. How is the fork(2) system call implemented on the 68K processors
without a memory management unit?
This is done by shadowing. This is copying the memory around as long as
both child and parent proces do exist. Although this seems very expensive,
it is not because most processes exec(2) almost immediately after the
fork(). But most terminal emulators who fork() en keep running loose.
18. Is there also a 64k+64k limit for minix 68k & minix 386?
For minix 68k, there isn't. For minix 386 there isn't provided you use the
proper compiler (This means no ACK)
19. Does minix have Berkely job control?
No. Nor does it have its associated signals like SIGSTOP, SIGCONT etc.
20. Does minix support TCP/IP and NFS
No. TCP/IP does exist as an experimental package. NFS is a dream for many
;-)
--
Glen Overby <overby@plains.nodak.edu>
uunet!plains!overby (UUCP) overby@plains (Bitnet)