[comp.sys.att] UNIX PC Problems

aglew@ccvaxa.UUCP (07/23/87)

		  Swap Problems with the 3B1/UNIX PC
		  ==================================

Well, I've just bought one of the 3B1's on sale, and I am concerned.

I've heard several stories about system problems if there is insufficient
swap space; and now it begins to sound like the mysterious error that
crops up with uucp running is also swap related.
	It sounds like 3B1 UNIX does not properly detect the end of
the swap device; most likely, it detects the out-of-swap-space error,
because it apparently kills processes, but likely has a boundary value
problem and is overrunning the end of some table related to swap.
(That's a bug I've seen in many UNIXes).

Seems to me like there are two things that need to be done: (1) find a
way to increase swap space (I've half a hope of running GNU Emacs on
this machine, and will need much more than the default 2.5M of swap),
and (2) locate the garbage planter on swap errors.

I've not received my machine yet, so am stuck. A friend of mine who was
a longtime 7300 user remembers that an early version of the UNIX
allowed swap size specification. Does anyone have such a disk around,
to disassemble?

[I can't wait to get my machine. Is anybody interested in putting
up a decent UNIX on it?]


Andy "Krazy" Glew. Gould CSD-Urbana.    USEnet:  ihnp4!uiucdcs!ccvaxa!aglew
1101 E. University, Urbana, IL 61801    ARPAnet: aglew@gswd-vms.arpa

aglew@ccvaxa.UUCP (07/23/87)

My friend (Mark Bellon) reports that on an earlier version of the
diagnostic disk you could (1) specify swap size, and (2) do a
hardware reformat of the disk, ie. rewrite disk block labels, etc.

Unfortunately, he threw out (reused) this disk when he received an update,
and was disappointed to learn that the update had less functionality.

Does anyone out there still have the diagnostic floppy that lets you
specify swap size, and reformat the disk?

				 ---

(Really pushing it, does anyone out there have "sawp-into-file" implemented
for the UNIX PC, as on Masscomp?)


Andy "Krazy" Glew. Gould CSD-Urbana.    USEnet:  ihnp4!uiucdcs!ccvaxa!aglew
1101 E. University, Urbana, IL 61801    ARPAnet: aglew@gswd-vms.arpa

richard@islenet.UUCP (Richard Foulk) (07/27/87)

> 
> [I can't wait to get my machine. Is anybody interested in putting
> up a decent UNIX on it?]
> 

I can't wait to get mine either.  I'd like to see BSD unix running on 
the 3B1, but the System V that comes with the system seems quite nice.  

From what I've seen so far on a friends machine there is a whole list 
of things you don't see on your garden variety unix ports.  Many that 
you'd most likely lose if you brought up a different flavor of unix.  
As an example the shared library is a great idea that I haven't seen 
anywhere else.  

Perhaps I'm overly impressed because I've used too many low-rent 
Unisoft unix boxes.  

-- 
Richard Foulk		...{dual,vortex,ihnp4}!islenet!richard
Honolulu, Hawaii

davidsen@steinmetz.steinmetz.UUCP (William E. Davidsen Jr) (07/27/87)

In article <31200002@ccvaxa> aglew@ccvaxa.UUCP writes:
|
|		  Swap Problems with the 3B1/UNIX PC
|		  ==================================
|
|I've heard several stories about system problems if there is insufficient
|swap space; and now it begins to sound like the mysterious error that
|and (2) locate the garbage planter on swap errors.
...
|I've not received my machine yet, so am stuck. A friend of mine who was
|a longtime 7300 user remembers that an early version of the UNIX
|allowed swap size specification. Does anyone have such a disk around,
|to disassemble?

It's the v2.5 maint disk, and I use it every time I put a larger
hard disk on my system. One of your friends must be a packrat and
still have it.
-- 
	bill davidsen		(wedu@ge-crd.arpa)
  {chinet | philabs | sesimo}!steinmetz!crdos1!davidsen
"Stupidity, like virtue, is its own reward" -me

andys@genesis.UUCP (a.b.sherman) (07/28/87)

There has been much discussion about increasing swap space on the
7300/3B1.  As a 3B1 user of over a year, I question the need.  The
problem alluded to in several of the postings was not a lack of swap
space but a bug in the kernel that caused the system to panic when
running uucico *WHILE RELATIVELY IDLE!!!!*  This has been fixed, and
the fixdisk is available from the hotline.  The symptom is
unexplained crashes (with uucico or uusched active) in the middle of
the night.  4:00 AM was a favorite time, leading it to be called
"The 4:00 AM crash bug".  Get more swap space if you need it, by all
means, but don't waste your disk if you don't need it.  Don't forget
that this system is demand paged.
-- 
andy sherman / at&t bell laboratories (medical diagnostic systems)
room 2h-097 / 480 red hill road / middletown, nj 07748
(201) 615-5708 / andys@shlepper.ATT.COM
...The views and opinions are my own.  Who else would want them?