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Date: Sun, 14 Mar 2004 11:37:13 -0500
From: "Justin Baugh, KSC" <baughj@discordians.net>
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Subject: Pernicious problem with vfork / qmail / qmail-scanner (RESOLVED)
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Justin Baugh wrote:

> I did some testing. I wrote a small program in C to fork off a 
> specified number of processes and leave them there. I find that 
> I can run exactly 39 processes as qmaild before tcpserver begins 
> to barf, saying it cannot fork.

So, after much testing & debugging:

* The problem only happens with tcpserver
* The problem is not replicable in any way under 5.2.1R
* The problem happens with any service/user with tcpserver, not just
   qmail-smtpd/qmaild

I set up a testbed on my home box with a vanilla qmail install, and I 
wasn't able to get it to choke up. As a workaround (until I can upgrade 
the other box to 5.2.1R) I am running qmail through xinetd /
tcpwrappers (heresy, I know), and all is well.

For reference, the box in question was at 5.1-RELEASE-p10, the 
vendor-supplied version.

Thanks,

-Justin