3b2-310 lost characters
James R. Van Artsdalen
and upgraded to 2.0.4 at the same time we did the hardware upgrade. We have
one serial board, and 1 megabyte of RAM. We had been running the console and
three of the serial ports on the serial board at 19.2Kbps (the other two
serial ports were run at 2400bps and 1200bps). With the -300 motherboard and
V.2.0, this worked fine.
After the upgrade, we began having trouble with the serial lines. Every so
often the system would get into a mode wherein it would lose characters on
the serial ports. When printing mail it would print some of the mail and
stop: almost as though the character output buffers were being lost. Once the
system began this there was no way to recover without rebooting. This
apparently did not affect operation of the CPU itself: the system would run
fine indefinitely after this started.
On the basis of some rumors I've upped the NCLIST value to 200 from 80 and
dropped the baud rate on the terminals to 9600bps from 19.2Kbps. The problem
has not occurred in two weeks (previous frequency was about twice a week).
Rumor also suggests that the problem can be fixed without rebooting by
re-pumping the serial card. I have not tried this.
The problem has been seen on a -310 with System V.2.1. It has not been seen
on a -300 to my knowledge. The -310 running V.2.1 has only seen the problem
once in a month of operation.
Has anyone else seen this problem, and does anyone know what the true cause
is? I am not confident that I have solved it with either change. I would
like to solve this. With our -300 we ran the computer for months between
reboots, but now we're restarting every couple of weeks.
--
James R. Van Artsdalen ...!decvax!dartvax!osi3b2!james Live Free or Die
randy
>
>After the upgrade, we began having trouble with the serial lines. Every so
>often the system would get into a mode wherein it would lose characters on
>the serial ports.
I have a 3b2/300 with 2 megs memory, and 3 ports cards. I have two
9600 baud terminals connected to console and contty. All the ports card have
2400 baud modems on them. What you describe happens about once a week with
out fail. When it happens, it happens on all ports, console included. Only
way to fix is to shutdown and restart. I have played with clists from 50 to
300 with no change. It did not happen until I upgraded to 2.0.4
Another strange thing with 2.0.4 is that a number of times a day,
the i/o system just *stops*! Processing continues on and characters echo
at the terminals, but nothing happens. From 30 seconds to 5 minutes
it just sits, then bang, every thing continues on as if nothing happened.
It seems to be disk i/o related. I can be sitting at the console when it
happens, look over at the modem that a uucp is going on, and watch the flow
go fine for about a half minute. Then it starts timing out, as if a buffer
got filled and had to go to the disk. Generally, uucp times out before the
system fires back up again. By various experiments, I have found a combination
of things agravate the problem. If I set NBUFS to over 300 *AND* any program
is set sticky bit, it runs rampant. I have had to un sticky /bin/sh, rnews,
vi and all others, or the system is unusable. Is it my 300 only, or is
this common?
--
.. that's the biz, sweetheart...
Randy Suess
chinet - Public Access UN*X
(312) 545 7535 (h) (312) 283 0559 (system)
..!ihnp4!chinet!randy
John Young
software, especially when running at high speeds. Call your
software support service for details. There is a new ports
board out called a High Performance Ports board (it has HPP
stamped on the front) which cures some of the performance
problems. I was not aware of a pre/post-2.0.4 boundary to
these problems.
David J. Carpenter
>What you describe happens about once a week with
>out fail. When it happens, it happens on all ports, console included. Only
>way to fix is to shutdown and restart. I have played with clists from 50 to
>300 with no change. It did not happen until I upgraded to 2.0.4
> Another strange thing with 2.0.4 is that a number of times a day,
>the i/o system just *stops*!
I get that about once a week also. I have a 300, and have upgraded to 2.0.4.
I haven't ever seen the i/o system just stop, though. The characters get
consistently lost in big chunks. Every time you do a screen refresh, maybe
every other chunk off 100 characters disappears. You can only reboot.
Must be a bug in the 2.0.4 tty driver...
--
...!ihnp4!chinet!qpsn!david
David Carpenter
[home] (312) 545-8076
[work] (312) 787-9343
John Young
characters on 3B2's I have been asked to withdraw my "advertisment"
of the new ports board I mentioned.
John Young
L.EICHNER
On page 2-2 of the WECO port board manual it says:
" Each card will support simultaneous output to four serial
ports at 9600 baud * with line occupancy less than 80% ...
or
*TWO* ports at 9600 at 100%
or
*FOUR* ports at 4800 at 100% ... "
There is no mention of compounded problems with more than one
port card, but this might be a factor as well..
"If you don't want to read the instructions
yourself, you should at least pay someone to
do it for you..."
Metro T. Sauper
I did not see the origional problem, but from the responses, it seems to
sound like a problem I had on my 3B2/400.
Symtoms:
At all terminals including console - Characters you type would not be echoed
back (i.e. not read). Repeated typing of a character might echo 1 in 10 times.
When echoing occured, sometimes groups of 3 & 4 characters would go through
at one time.
Cause:
We had a US Robotics modem connected to the contty port. The modem was set
to echo characters sent from computer to pace the dialing strings. The DCD
line was tied high so the 3B2 would talk to the modem. If the current user
broke the connection without ^D (i.e. did not log off) the computer could
not tell since the DCD line was tied high. The modem echoed DISCONNECT^m.
The computer echoed DISCONNECT not found -- which was echoed back by the
modem -- which was echoed back by the computer in addition to another
DISCONNECT not found -- .............
Soon there is a olympic caliber event to see who will give up first, the
computer or the modem. The result to the rest of the users on the system is
no input buffers to read into.
Solution:
1. If this happens, check to see if the transmit are recieve lights are on
solid while the OH (off hook) light is out. If this is the case, turn
off teh modem for a while to wait for the 3B2 to flush its buffers.
Everything should come back to normal.
2. Turn of the command echo in the modem. I don't think you need it anyway.
The session will still be live after the connection is broken, but after
the DISCONNECT not found, the line is idle.
This had caused me no end of headaches until i figured it out. Any comments
on what I observed are welcome.
Metro T. Sauper, Jr.
ihnp4!ll1!bpa!asi!metro
James R. Van Artsdalen
>
> On page 2-2 of the WECO port board manual it says:
>
>
> There is no mention of compounded problems with more than one
> port card, but this might be a factor as well..
>
> "If you don't want to read the instructions
> yourself, you should at least pay someone to
> do it for you..."
Thanks for your kind assistance in helping the three 3b2 owners who posted
messages saying they had this problem. I don't know what we would have done
without your insights... :-<
On the more reasonable side, you should note that it appears that everyone had
trouble AFTER they "upgraded" from 2.0 to 2.0.4 or 2.1.0. People running 2.0
never have this trouble apparently. This indicates to me a bug in the kernel
or the "ports" code. I may try to find my old "ports" code from 2.0 for the
tty and see if it works with 2.0.4 (it might not work but trying won't hurt).
I can be reasonably confident that output baud rate isn't a problem, but input
rates, and we just don't have any fast typists :-) .
The bottom line is that I had a machine that ran for months without a glitch
or reboot. One day I upgrade, being promised all manner of minor bug fixes,
and to my regret I now have a system that must be rebooted (or have the ports
re-pumped) every other week or so. I have not had to reboot in about three
weeks now, but even so it is a problem for me, and other sites have to reboot
more frequently that I do. Were the old system not four revisions back I would
be sorely tempted to revert.
--
James R. Van Artsdalen ...!ut-ngp!utastro!osi3b2!james Live Free or Die
James R. Van Artsdalen
>
> I did not see the origional problem, but from the responses, it seems to
> sound like a problem I had on my 3B2/400.
[description of problem]
> We had a US Robotics modem connected to the contty port. The modem was set
> to echo characters sent from computer to pace the dialing strings. The DCD
> line was tied high so the 3B2 would talk to the modem. If the current user
> broke the connection without ^D (i.e. did not log off) the computer could
> not tell since the DCD line was tied high. The modem echoed DISCONNECT^m.
[Description of characters echoed forever and solution to it all]
> This had caused me no end of headaches until i figured it out. Any comments
> on what I observed are welcome.
>
> Metro T. Sauper, Jr.
> ihnp4!ll1!bpa!asi!metro
This could be a problem, but not in this case. Our modem is set up not to
echo the the characters from the computer when dialing. In addition I have
a little black-box to cause the carried detect to pulse low whenever carrier
is lost (about a 30 second pulse). Otherwise carried detect line into the 3b2
stays high. Fixes that incredibly annoying kernel bug in the 3b2 that prevents
the 3b2 from talking to modems when carrier detect is low...
--
Richard Kuhns
I've experienced this problem on a 3b2/310 running 2.0.4, but I have yet
to encounter it on either of our 400s (also running 2.0.4). Rebooting
has always cured it -- I haven't waited more than about 10 minutes to
see if it would disappear.
Someone (sorry, I lost the name) said that he'd experienced this problem
due to a USR modem with echo turned on. I once connected a 3b1 to one
of our 400s via a direct connection, with getty running on both ports
(oops :-) ). I did NOT experience this problem then. The system slowed
down most remarkably, but I did not loose any characters. Unplugging the
cable restored everything to normal, with no noticeable side effects.
--
Rich Kuhns {ihnp4, decvax, etc...}!pur-ee!pur-phy!mrstve!rjk
James R. Van Artsdalen
>
> I've experienced this problem on a 3b2/310 running 2.0.4, but I have yet
> to encounter it on either of our 400s (also running 2.0.4). Rebooting
> has always cured it -- I haven't waited more than about 10 minutes to
> see if it would disappear.
What's the difference between a 3b2-310 and a 3b2-400? I thought they were
the same except for the cabinet.
--
Richard Kuhns
>[ ... ]
>What's the difference between a 3b2-310 and a 3b2-400? I thought they were
>the same except for the cabinet.
>--
>James R. Van Artsdalen ...!ut-ngp!utastro!osi3b2!james Live Free or Die
Generically speaking, I think you're right. Our 3b2/400s have MAUs -- can
you put a MAU on a 310?
John Young
Larry Lippman
> I once connected a 3b1 to one of our 400s via a direct connection, with
> getty running on both ports (oops :-) ). I did NOT experience this problem
> then. The system slowed down most remarkably, but I did not loose any
> characters. Unplugging the cable restored everything to normal, with no
> noticeable side effects.
I have accidently done the same thing myself, and the results are so
astounding on a 3B2 that even your statement qualifies as the understatement
of the year!
==> Larry Lippman @ Recognition Research Corp., Clarence, New York
==> UUCP: {allegra|decvax|rocksanne|rocksvax|watmath}!sunybcs!kitty!larry
==> VOICE: 716/688-1231 {hplabs|ihnp4|seismo|utzoo}!/
==> FAX: 716/741-9635 {G1,G2,G3} "Have you hugged your cat today?"
Walt Pesch
- Only 4 expansion slots instead of the 12 that are in the 400 cabinet.
- 2 Meg boards won't fit, thereby giving a max memory of two 1 Meg boards.
- Only one drive will fit internally to cabinet, any more will have to
be placed in an XM.
- Only the floopy drive is provided - a second floopy drive or a
cartridge tape drive will also have to be housed in an XM. (BTW, the
XM will support up to three units in it of which only two can be
removable medium.)
Walt Pesch
ihnp4!cuuxb!wbp
Admin
The 3B2/310 is the same Systems board and software. The difference,
other than the cabinet, is the firmware and the amount of memory and I/O
ports they will address.
Charlie Boykin
..ihnp4!killer!sysop