[comp.unix.ultrix] excessive "init" forking

eric@batcomputer.tn.cornell.edu (Eric Fielding) (07/25/89)

We have a nice new DECstation 3100 running Ultrix 3.0 and DECwindows.
Unfortunately it is running so slowly as to be essentially useless, for
what I believe are three reasons. One it has "only" 8 MB of memory. Two it
has only enough local disk space (100 MB) for the swap partition and must get 
all of its system and files across the Ethernet. Both of these hardware 
deficiencies are being corrected by upgrades. The question I have for the net
is about a software problem. It appears that "/etc/init" is constantly forking
off copies of itself, at a rate of about 50-100 times a minute. Each process
lasts only a short time but meanwhile uses several hundred K of memory. At
any one time "ps -aux" shows 5-10 "/etc/init -a" processes running. It seems
like this constant process creation is greatly magnifying the hardware
deficiencies to the point where the machine is unusable. I suspect that
there is something wrong with the way the system is set up, but I don't know
where to start looking. Thanks for reading this lengthy message.
				++Eric Fielding
Eric@geology.tn.cornell.edu

grr@cbmvax.UUCP (George Robbins) (07/26/89)

In article <8490@batcomputer.tn.cornell.edu> eric@geology.tn.cornell.edu writes:
> We have a nice new DECstation 3100 running Ultrix 3.0 and DECwindows.
> Unfortunately it is running so slowly as to be essentially useless...
> 		.... It appears that "/etc/init" is constantly forking
> off copies of itself, at a rate of about 50-100 times a minute. Each process
> lasts only a short time but meanwhile uses several hundred K of memory. At
> any one time "ps -aux" shows 5-10 "/etc/init -a" processes running.

Sounds pretty perverse.  If init is constantly forking, it would seem that
it's constantly trying to set something up that is failing.  Maybe look
in syslog for clues, you don't mention anything coming out on the console...

Is /etc/ttys reasonable?  You're not trying to spawn off stuff on serial/
psuedo/LAT devices that aren't defined in /dev or are otherwise defective?

Any resource problems?  Swap space or virtual memory size?  Does this
happen from moment 1, or only take off after some random delay/event?

Of course this could be something intrinsic to the operation of DECwindows,
something of which I know nothing, but suspect uses some hooks into init
since there are already funny "window manager" hooks in BSD init before
DEC got to it.

-- 
George Robbins - now working for,	uucp: {uunet|pyramid|rutgers}!cbmvax!grr
but no way officially representing	arpa: cbmvax!grr@uunet.uu.net
Commodore, Engineering Department	fone: 215-431-9255 (only by moonlite)

envbvs@epb2.lbl.gov (Brian V. Smith) (07/26/89)

In article <8490@batcomputer.tn.cornell.edu>, eric@batcomputer.tn.cornell.edu (Eric Fielding) writes:

 [...]

< The question I have for the net
< is about a software problem. It appears that "/etc/init" is constantly forking
< off copies of itself, at a rate of about 50-100 times a minute. Each process
< lasts only a short time but meanwhile uses several hundred K of memory. At
< any one time "ps -aux" shows 5-10 "/etc/init -a" processes running. It seems
< like this constant process creation is greatly magnifying the hardware
< deficiencies to the point where the machine is unusable. I suspect that
< there is something wrong with the way the system is set up, but I don't know
< where to start looking. Thanks for reading this lengthy message.

Check your /etc/ttys to see what kinds of things are being started by 
init.  There should only be gettys and possibly window= lines (for the
old method of starting the X server).
One or more of those processes are dying, and init is starting it/them
up again.
_____________________________________
Brian V. Smith    (bvsmith@lbl.gov)
Lawrence Berkeley Laboratory
We don't need no signatures!

eric@batcomputer.tn.cornell.edu (Eric Fielding) (07/27/89)

Newsgroups: comp.unix.ultrix
Subject: Re: excessive "init" forking
Reply-To: fielding@geology.tn.cornell.edu
Distribution: na
Organization: Department of Geological Sciences, Cornell University

In a recent article I (eric@geology.tn.cornell.edu) wrote:
>...deficiencies are being corrected by upgrades. The question I have for the net
>is about a software problem. It appears that "/etc/init" is constantly forking
>off copies of itself, at a rate of about 50-100 times a minute. Each process
>lasts only a short time but meanwhile uses several hundred K of memory. At
>any one time "ps -aux" shows 5-10 "/etc/init -a" processes running. It seems...

George Hartzell (hartzell@boulder.Colorado.EDU) figured out the problem. My
/etc/ttys file was set up wrong. It had the ttyp0-ttyp9 configured "on" when
they should have been "off". The "init" process kept trying to create "getty"s
to look at those pseudo-terminals. This was using up valuable memory on our
un-upgraded (so far) 8 MB DECstation and causing it to crawl. It is now running
fine. (Though we still plan to order more memory when DEC starts selling it
for Consortium prices or if they don't from someone else...)

Thanks to the other folks who sent suggestions, too!

				++Eric Fielding