Welcome to comp.unix.sysv386 (AKA Frequently Asked Questions)
Conor P. Cahill
cpcahil at virtech.uucp
Mon Nov 5 12:20:05 AEST 1990
Welcome to the comp.unix.sysv386 newsgroup. This newsgroup (actually the
former comp.unix.i386 newsgroup which was renamed to this group) was founded
to perpetuate discussions of the various unix systems running on the
Intel 80386 architecture.
This article contains the answers to some Frequently Asked Questions
often seen in comp.unix.sysv386.
Before posting a question to this newsgroup, PLEASE read through this
posting, the Frequently Asked Questions posting in comp.unix.questions,
and finally the various postings in news.announce.newusers.
Last Modified: $Id: freq.ques,v 1.5 90/10/01 23:10:04 cpcahil Exp $
This article includes answers to:
1. What is this group for?
2. Which Unix should I buy?
3. Is there a BSD port for the 386 available anywhere?
4. What hardware works with brand X Unix and/or X11
5. How do I rewind or retension a cartridge tape?
6. How do I get a second serial port working?
7. How do I get fast serial line throughput with stock asynch ports?
8. Is there a port of X11 R3/4 available for whatever?
9. What are good intelligent multi-port serial card solutions?
10. Where do I get troff from?
11. Why doesn't vi work on large files?
12. How do I increase my ulimit?
13. How do you set up a port for both dial-in and dial-out access?
14. How do I setup a global environment variable that even gets set
in the /etc/rc*/* scripts.
15. How do I get more than 8 virtual terminals to work on the console?
16. Why do I get the error "ps: unlink() error" every once in a while?
17. How do I set up more than 4 partitions on the disk drive
18. Why do I run out of inodes on some filesystems when I know I don't
have that many files?
19. What is the minimum hardware for running Unix on a 386?
20. Will a caching controller be a good investment?
21. How many users can I run on my 386?
22. What is the bandwidth of an AT Bus?
23. Can Unix make use of memory in 16 bit AT bus slots?
24. How do I fix the error "Out of DOS Inodes" ?
25. Where can I get the K-Shell (aka ksh)?
Before I start on the answers, I will state that there is NO GUARANTEE as
to the correctness and/or appropriateness of these answers. If you intend
to try one, BE SURE TO HAVE A BACKUP of your system first.
My current system is Interactive's ISC UNIX 2.2. I have tested
most of the responses on this system. If you find that another system
requires a different response, please send me mail explaining what is
required on your system (you might also want to tell me the OS and version).
1. What is this group for?
This group was formed to discuss the various implementations of UNIX
on the Intel 386 architecture. This includes SCO Unix, 386/ix,
ISC UNIX, ESIX, Dell, Bell Tech (now Intel) Unix, Microport Unix,
and, of course, AT&T and any others that I have forgotten.
Since no vendor intends to make a 486 specific version of their OS,
the use of the various UNIX products on the i486 will also be
discussed.
2. Which Unix should I buy?
This is a hard question. Few people have access to all of the
available Unix implementations and without that access it is
hard to be able to recommend any one over the other. You should
consider the following factors in making your decision:
1. price
2. compatibility with existing software
3. compatibility with other operating systems
4. ease of use/control (administration menus)
5. performance
You must decide which of those factors is more important to you.
Most, if not all, application packages developed for one UNIX will
run on one of the others. If you find one that does not, blast the
developers because there is no reason for them to use any vendor
specific code in their applications (and, IMHO it was a real stupid
decision on their part).
3. Is there a binary BSD port for the 386 available anywhere?
No. However, System V Release 4.0 will have many BSDisms including
symbolic links, job control, BSD file system, sockets (implemented
on top of streams). It will also contain the SunOS memory mapped
files, the Korn shell, and many other nifty things.
These are now starting to ship (usually beta releases) to end-users
by Intel, Microport, and UnixHOUSE. I haven't seen these releases,
nor heard any reports from those that have recieved them.
One thing that should be noted here is that the System V R4 release
has MAJOR changes over the R3 releases and probably won't be stable
for a while. If you want a stable system, I would suggest that you
continue to use a R3 until the second release of R4 systems (6-9 mos
or so).
BSD 4.4 will support the 386 architecture as a base system. This
means that vendors will have a base BSD system that could be used
to make a BSD binary release for this architecture. There are
several reasons why this probably won't occur:
1. SVR4 will be enough BSD to satisfy most people
2. BSD kernel would have to be modified to support the
386 ABI or else it would be closed out of a major
portion of the 386 market.
3. This is a brand new port and it can be expect that
there will be significant problems with the stability
of any new product. This puts it around 2 or 3 years
behind the other 386 Unixs in this respect.
Of course, this does not mean that you will never see BSD4.4 on
a PC (since you will probably see it if you are somehow connected
with a university that gets BSD source). It just means that there
probably wont be a commercial binary release available to the
general public.
The other possibility is MACH. MACH is 4.3BSD compatible and has
the 386 as one of it's target environments, but since it includes
much of the BSD kernel, it still requires a standard BSD licensing
(which is actually a requirement for an AT&T version 7 license).
At least one company (Mt Xinu) has announced that they will support
(and distribute) the MACH source code (assuming you have the
appropriate license) but there have been no announcements about
commercial binary distributions.
4. What hardware works with brand X Unix and/or X11
The correct answer to this is a recommendation to call the
distributor of the X11 that you intend to buy. The list of
devices changes all the time and attempting to maintain a list
here would be ludicrous.
5. How do I rewind or retension a cartridge tape?
This depends upon the OS and tape device. The standard at&t
distribution includes the tapecntl program (it is even documented
in the 386/ix manuals), but most of the 386 unix products do not
provide it. SCO UNIX has the "tape" program.
The next place to look is the tape driver manufacturer. Archive
does provide a "ctape" program which can perform this function.
If your OS manufacturer doesn't provided it and your tape
manufacturer doesn't provide it, you need to home grow it yourself.
6. How do I get a second serial port working?
SCO Unix and Xenix come pre-configured to work with two serial port
devices. AT&T Unix auto-configures the number of serial ports.
The rest of the Unix offerings do not and must be re-configured to
turn on the second serial port.
The asy file in /etc/conf/sdevice.d contains the kernel configuration
information for the standard asynchronous ports. The file should
look something like:
asy Y 1 7 1 ....
asy N 1 7 1 ....
This shows that the first asy is enabled, while the second is
disabled (the N in column 2). Change this file to:
asy Y 2 7 1 ....
asy Y 2 7 1 ....
and rebuild the kernel using kconfig or /etc/conf/bin/idbuild as
appropriate for your system. Be sure to check the interrupt number
and i/o port addresses to ensure they are correct and don't conflict
with other devices. See sdevice(4) for more info.
Note that the change from a 1 to a 2 in column 3 enables the modem
control ports which can be used for uugetty.
7. How do I get fast serial line throughput with stock asynch ports?
The stock serial ports usually will drop characters when run at
high speeds with incomming data. The best way to fix this is to
add the "FAS" driver to your system. (FAS stands for Final
Asynch Solution). This driver (version 2.07) was posted to
comp.unix.sysv386 in September of 1990.
The Readme for the FAS driver suggests that you also replace the
16450 uart chips on your asynch card with 16550s (I think the
cost runs around $20). The 16550s provide a 16 byte FIFO which
allows operation at high speeds without loosing characters.
SCO Unix, ESIX, and ISC UNIX are all reputed to support the 16550
in FIFO mode, so you probably can make this change without having
to change the drivers. See your OS documentation for more info.
8. Is there a port of X11 R3/4 available for whatever?
X11R3 is available from all of the 386 UNIX distributors.
There are no releases fully based upon X11R4 yet.
9. What are good intelligent multi-port serial card solutions?
This is yet another religous issue. The following cards are
available for AT bus systems. Note that the cards are listed
in alphabetical order and that this should not be taken as a
recommendation of any one card over the others.
Bell Tech (now Intell)
BT has three serial port solutions: ICC, ACE, and HUB.
The ICC card looses data at incomming speeds > 19200. It
locks up about once or twice a week, but is easily restarted
since BT provides a program that can reset the card without
rebooting the system. For normal terminal operation the
card is satisfactory. Price was around $1500 when I bought
it a couple of years ago.
The ACE card is reported to be "bad beyond belief" with
hanging problems caused by timing problems on the card.
The HUB is a non-intelligent card that is "rock solid" and
will provide 6 ports. However, since it is non-intelligent
it will place a load on the system.
Computone
Computone provides a series of serial port solutions. I
have no experience/pricing info on these cards.
Digiboard
Digiboard provides a series of serial port solutions. I
have no experience/pricing info on these cards.
Equinox
Equinox has two serial port solutions: the Megaport 12, and
Megaport 24. Each board is reputed to be capable of running
all ports at full 38400 simultaneously. The 24 port cards
runs around $1200. Installation is a snap, no jumpers to
set, no interrupts required for the board. The board
can be installed to use memory between 640K and 1 MB for
communications between the board and the system.
The board runs fine. Input/output port sharing is supported.
Maxpeed
Maxpeed has an 8 port card that will run any of the ports
at speeds up to 38.4K. The card retails for 795, but is
usually available at $500 to $550. I lost data when
receiving data as speeds > 9600 baud. VPIX did not
run correctly on my wyse 60's. I contacted customer
support and got the response "it works fine on other
machines".
Other than the vpix problem I had this board provides
good support for 8 terminals/printers at a low price.
Specialix
Specialix provides a series of serial port solutions. I
have no experience/pricing info on these cards.
Consensys
Consensys has two serial port solutions in their POWERPORTS
line. Each POWERPORTS intelligent main card supports up to
8 ports and can optionally accept an 8-port daughtercard.
Each main card takes a 16-bit slot; the daughters don't
require backplane access, but they do consume a slot cover.
Each port is supposed to be able to handle 38.4, but there
can be problems when driving Trailblazers from a daughter
port.
They also provide a multiple-session-per-terminal feature.
You can drive up to 8 independent sessions from each physical
terminal, toggling between sessions via control keys.
The only downside is that you must go through a two-minute
reconfiguration of the ports software if you switch terminal
types on a port, since the card must load the appropriate
termcap/terminfo. They also provide software for transparent
printing to a printer attached to an aux port on one of the
terminals.
List prices range from $850 to $2,000 depending upon port
and board RAM configurations.
10. Where do I get troff from?
You can but the Documenters Workbench package from your
Unix distributor, or a substitute package from a third party
venor.
The problem with the standard packages is that they do not support
most of the currently available printers in troff mode.
The third party packages seem to fill this niche quite well.
These include:
Eroff $795
SoftQuad Publishing ???
Jetroff $69 (personal)/$119 (commercial)
Psroff $0
I have only used Eroff and it works quite well. I have heard good
words about SoftQuad and Jetroff. Psroff was posted to
comp.sources.unix late last year.
11. Why doesn't vi work on large files?
There are two possible problems. The first problem may be
that you are running into a ULIMIT problem. See the discussion
under question 12 to figure out how to change/correct it.
If this is not the probem, you may be running into a bug/feature
of some VIs. The problem is that there are compiled in limits
as to the number of lines in the data file.
This problem is known to exist in the following Unix packages:
AT&T System V Rel 3.2
Bell Technologies System V Rel 3.2 (was ok in 3.1)
12. How do I increase my ulimit?
For those of you who don't know, the ulimit is the limit in the
number of blocks that can be written to a file. This is intended
to be a mechanism to stop a run-away process from eating up all the
disk space available on your system.
Both SCO Unix and SCO Xenix start out with a ulimit of 2097152 which
means that you probably won't have a problem with the ulimit on
these operating systems. However, if you have one of the AT&T
derived operating systems, this limit will usually default to
2048 or 4096 and it has a hard limit of 12288. This can be
unacceptable for systems that will have moderate to large database
files and will therefore need to be increased.
1. If your desired limit is > 12288(6MB):
Edit /etc/conf/cf.d/mtune to change the following line:
ULIMIT 3072 2048 12288
to:
ULIMIT 3072 2048 xxxxx
where xxxxx is the limit you desire.
2. Edit /etc/conf/cf.d/stune to add/change the following line:
ULIMIT xxxxx
where xxxxx is the limit you desire. Note that this step can
be performed in the kernel configuration software (i.e.: kconfig
for 386/ix).
3. Edit /etc/default/login to delete the ULIMIT line.
4. Rebuild the kernel and reboot.
13. How do you set up a port for both dial-in and dial-out access?
There are two ways to do this. Most intelligent boards provide
two devices for every port: one with and one without modem
controls. The modem control ports are used for getty, while
the corresponding non-modem control lines are used for cu,
uucp, kermit, etc. This is the easiest mechanism to configure
and use (provided the device driver works properly).
The SCO and ESIX systems and the FAS driver provide modem control
ports which can be used in the same manner.
The second solution is to use the uugetty software. uugetty
is a replacement for getty that uses uucp/cu locks to control
access to the port. In order to work properly, the port must
have modem control support.
386/ix and ESIX have support for the modem control on the serial
ports, but does not configure these devices automatically. You
must mannually create the ports using the following commands:
For 386/ix:
mknod /dev/ttym0 c 3 16
mknod /dev/ttym1 c 3 17
For ESIX:
mknod /dev/ttyM0 c 3 128
mknod /dev/ttyM1 c 3 129
A better way to do this would be to modify the /etc/conf/node.d/asy
file so that it creates the modem control ports.
14. How do I setup a global environment variable that is set for
all programs/shells (including the /etc/rc*/* scripts?
/etc/init reads the /etc/TIMEZONE file at start up time. The
first 5 or so variables in this file are placed into the global
envionment for all processes started by init (this includes the
rc scripts, cron scripts, etc). In addition many OS scripts
will "source" this file.
15. How do I get more than 8 virtual terminals to work on the console?
SCO provides 10-12 MultiScreens(TM, I believe). Depends on the
keyboard and how much memory is available. This is configured
using the "configure" script.
Interactive (and probably the other 386 Unix ports) come set up to
use up to 8 VTs while the driver will support up to 15. To make
the changes to allow the use of more than 8 do the following:
Assuming you want new_max number of vt's (new_max must be <= 15) you can
do the following....
a. Modify the NKDVTTY line in /etc/conf/cf.d/mtune to look like:
NKDVTTY 8 8 new_max
b. Add the following entry to /etc/conf/cf.d/stune:
NKDVTTY new_max
c. reconfigure the kernel
d. add new devices to /dev. The device names and numbers should be as
follows:
Major device number: Value in 6th column of the "kd" entry in
/etc/conf/cf.d/mdevice file. (On my system
it is a 5).
Minor device numbers are generated using the following mechanism:
/dev entries Minor Device Number
------------ --------------------------
vt00 - vt07 (vt number) * 32)
vt08 - vt14 (vt number - 8) * 32) + 16
where vt number is the two digits in the device name
e. Add the appropriate entries to /etc/conf/cf.d/init.base
f. If you want to see "VT#" on the login prompt for each VT, you must
add entries to /etc/gettydefs for each vt. See the entry for VT02
for an example.
g. reboot the system
16. Why do I get the error "ps: unlink() error" every once in a while?
This error is caused by the ps program being unable to remove
the /etc/ps_data file. This is usually a permissions problem
on /etc or /bin/ps. The files and/or directories should
be set with the following modes:
drwxrwxr-x 20 root sys 3968 Apr 29 08:36 /etc
-r-xr-sr-x 1 root sys 21472 May 22 1989 /bin/ps
In english:
/bin/ps must be mode 2xxx (set-gid)
/bin/ps must have the same group as /etc (usually sys)
/etc must be group writable
17. How do I set up more than 4 unix partitions on the disk drive
Under 386/ix (and Esix) a single "fdisk" partition can contain
up to 16 unix partitions (including swap, alternates, and reserved).
However, the default disk configuration software will only set up
up to 4 partitions for use as file systems. This can be bypassed
using the following manual procedure:
This is slightly different if you are talking about the
boot drive as opposed to the second drive.
For the boot drive, use the installation software to set up
the root (and /usr, if you are combining them) partition as
you need it to be. Then place the rest of your disk into
the last partition.
For the second drive, use the system administration shell
to set up the disk and set up the first partition as you
want it to end up. Place the rest of the disk into a single
partition.
The rest of this applies to either disk. I will show you the
steps required to add 3 partitions on the first drive.
a. Make a backup of your system!!!
b. Make sure you made a backup of your system!!!
c. modify the /etc/inittab so that your system boots up into
single user mode. To do this you change the initdefault
line to be something like:
is:s:initdefault:
Note the 's' between the first set of colons.
d. reboot the system
e. Look at the /etc/partitions file and determine the name
of the big partition you created. For my system this was:
usr2:
partition = 3, start = 129808, size = 1187914,
tag = USR, perm = VALID
Since we want to break that partition up into smaller
partitions, we need to delete it from the disk.
the remainder of the disk. The following command is used:
/etc/mkpart -p usr2 disk0
The "disk0" comes from the first line in the /etc/partitions
file which contains the header information for the disk drive. If
you are working on the second disk drive you will find a second
device stanza header just like the one for disk0: somewhere in
the middle of the file.
When you run mkpart you will probably get some message saying
that your changes won't take effect until you rebbot. This is
ok. You don't need to reboot yet.
f. Now you must edit the /etc/partitions file to set up the
partition stanzas for your new partitions and delete the
stanza for the /usr2 partition. If your /usr is not part of
your root, you might want to mount /usr so that you can
edit the files with vi. I added the following entries:
a:
partition = 3, start = 129808, size = 243600,
tag = USR, perm = VALID
b:
partition = 4, start = 373408, size = 311978,
tag = USR, perm = VALID
c:
partition = 5, start = 685386, size = 469768,
tag = USR, perm = VALID
d:
partition = 6, start = 1155154, size = 162568,
tag = USR, perm = VALID
If some partitions already exist (like alternates or
reserved) you must skip these and add your entries with
partition numbers above the existing partitions. If
you do add entries > partition 7, you must mknod the
extra disk devices as follows:
mknod /dev/dsk/0s8 b 0 8
mknod /dev/dsk/0s9 b 0 9
mknod /dev/dsk/0s10 b 0 10
mknod /dev/rdsk/0s8 c 0 8
mknod /dev/rdsk/0s9 c 0 9
mknod /dev/rdsk/0s10 c 0 10
The key parts of these entries are the label, partition
number, start, and size. Be sure that your values do not
collide and that the start of each successive partition is
equal to the summation of the start of the current partition
and it's size.
g. Now to make all of the new partitions run the following
commands:
/etc/mkpart -P a disk0
/etc/mkpart -P b disk0
/etc/mkpart -P c disk0
/etc/mkpart -P d disk0
h. reboot the computer. Use the command "uadmin 2 0" to
halt the system from single user mode.
i. Make the file systems for each of the partitions:
mkfs /dev/rdsk/0s3 243600
mkfs /dev/rdsk/0s4 311978
mkfs /dev/rdsk/0s5 468768
mkfs /dev/rdsk/0s6 162568:63000
Note that since the /d partition is to be my news partition
I have overridden the default number of inodes created on
the filesystem.
j. Label the file systems:
labelit /dev/rdsk/0s3 a disk0
labelit /dev/rdsk/0s4 b disk0
labelit /dev/rdsk/0s5 c disk0
labelit /dev/rdsk/0s6 d disk0
k. Modify /etc/fstab. Delete the entry for /usr2 and add
entries for the new file systems. My new /etc/fstab file
looks like:
/dev/dsk/0s3 /a
/dev/dsk/0s4 /b
/dev/dsk/0s5 /c
/dev/dsk/0s6 /d
l. Make the mount points:
mkdir /a /b /c
m. If desired, change the /etc/inittab file initdefault
entry back to what it was before.
n. run "telinit 2" or "init 2" (or 3 for those of you
with a network)
All done.
18. Why do I run out of inodes on some filesystems when I know I don't
have that many files?
It's a known bug. Corrected in AT&T's 3.2.1 etc..., ISC 2.2,
and in some binary patches, previously posted here, for
Microport 3.0e and ISC 2.0 (and Microport SV/AT). If you
have it, write hate mail to your supplier's expensive QA
department... It has been known for years.
19. What is the minimum hardware for running Unix on a 386?
A 386SX, 4 MB RAM, 40MB Disk, monochrome adaptor and monitor.
You can have this for little over $1000 mail order nowadays.
Using RLL is advisable, and does not cost you more.
With Xenix, you can live with as little as 2MB.
You will need additional space for any packages that you wish
to install (especially the development system and X window
packages).
20. Will a caching controller be a good investment?
The question is not easy to answer. Some believe that
you'd do better by just adding the same memory to central
memory and expand the buffer cache. On many machines that are
already at the limit of 16 MB this cannot be done and so
the caching controller becomes a good option.
WARNING: Caching controllers that are not write-through must
be protected by a UPS or you could find your system horribly
trashed when power is lost during heavy disk i/o.
21. How many users can I run on my 386?
On a suitably configured (read: multiple fast discs, ESDI
or SCSI controller, many MBytes of RAM), quite a lot,
depending on many factors. At least a dozen. As many as
as three dozen doing light sw developement or similar things.
22. What is the bandwidth of an AT Bus?
Over 5 MBytes per second. As an IO-memory bus, that's still
plenty. Most peripherals don't go over 1 MByte per second.
As a CPU-memory bus, no way.
23. Can Unix make use of memory in 16 bit AT bus slots?
Yes, but the slowdown is really impressive. Don't do it.
When you buy your machine, make sure that you can put in
1MBit chips, and that you can stuff at least 8MBytes on
the motherboard or the 32 bit memory board without buying
anything extra, and that you can go all the way to 16 MBytes
(or what you see as your maximum) without throwing away
any chips that are already installed.
24. How do I fix the error "Out of DOS Inodes" ?
This error message is telling you that the kernel driver for
the DOS file system is out of inodes. This configuration parameter
is NDOSINODE, but it is not in the default setup for 386/ix. To
fix the problem do the following:
1. Run /etc/kconfig
2. Select "configure a kernel"
3. Select add tunable parameters
4. Specify NDOSINODE
5. Specify 500
It will tell you NDOSINODE is a new parameter and ask you for
the minimum, maximum and default. Acceptable numbers are: 100,
1000, 200, respectively.
To avoid kernel compilation warnings about NDOSINODE being
re-defined you sould edit the /etc/conf/pack.d/dos/space.c file
and move the line:
#define NDOSINODE 200 /* DOS-FSS inodes array */
to be after the #include of config.h. You should also add a #ifndef
NDOSINODE before that line and a #endif after it.
So that section of the file will now look like:
#define MINSCTRSHFT 9 /* Minimum sector shift */
#define MAXSCTRSHFT 10 /* Maximun sector shift */
#define NDOSFILSYS 5 /* DOS-FSS superblocks array */
#include "config.h" /* for overriding above parameters */
#ifndef NDOSINODE
#define NDOSINODE 200 /* DOS-FSS inodes array */
#endif /* NDOSINODE */
unsigned char minsctrshft = MINSCTRSHFT;
25. Where can I get the K-Shell (aka ksh)?
There are several sources where one can obtain a working ksh for 386
based systems. These include the following:
* get source from the AT&T toolchest (approx $3,000 for a full
site license)
* get the MKS trilogy (approx $130) which includes a home-grown
substitute ksh.
* get gnu-BASH which has lots of the functionality and is free.
* get the KSH from Aspen Technologies
At least one of the System V R3 releases (namely Microport) included
a ksh. The base port of System V R4 includes the ksh as one of its
standard shell, so if you wait a bit, it will be part of the base
system.
----------------------------------------------------------------------------
If you have suggestions or corrections for any of these answers, please send
them to ...!uunet!virtech!cpcahil.
--
Conor P. Cahill (703)430-9247 Virtual Technologies, Inc.,
uunet!virtech!cpcahil 46030 Manekin Plaza, Suite 160
Sterling, VA 22170
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