No workie.  The limits get set.  And if I change it so it ignores the
problem and compiles anyway, it crashes on when the 510th qmail-remote
starts.  I know it's possible to do, there are some kernel patches to get
around this, but they were for kernel 2.2.  I thought that maybe this was
something that was able to be set on the fly in 2.4, but I guess not.
Here's the output of a few commands:

[root at austad qmail-1.03]# cat /proc/sys/fs/file-max
65536
[root at austad qmail-1.03]# cat /proc/sys/kernel/threads-max 
8192
[root at austad qmail-1.03]# ulimit -a
core file size (blocks)     0
data seg size (kbytes)      unlimited
file size (blocks)          unlimited
max locked memory (kbytes)  unlimited
max memory size (kbytes)    unlimited
open files                  65536
pipe size (512 bytes)       8
stack size (kbytes)         unlimited
cpu time (seconds)          unlimited
max user processes          4096
virtual memory (kbytes)     unlimited
[root at austad qmail-1.03]# ./chkspawn 
Oops. Your system's FD_SET() has a hidden limit of 1024 descriptors.
This means that the qmail daemons could crash if you set the run-time
concurrency higher than 509. So I'm going to insist that the concurrency
limit in conf-spawn be at most 509. Right now it's 2048.
[root at austad qmail-1.03]# 



> -----Original Message-----
> From: Rob Bajorek [mailto:rob at tatsumaki.org] 
> Sent: Friday, October 19, 2001 3:35 PM
> To: tclug-list at mn-linux.org
> Subject: Re: [TCLUG] FD_SET() limits in 2.4 kernel
> 
> 
> Sorry, you also have to set ulimit higher.
> 
> Example:
> $ ulimit -Hn
> 1024
> $ ulimit -n
> 1024
> 
> As root:
> 
> # echo 65536 > /proc/sys/fs/file-max
> # ulimit -Hn 65536
> # ulimit -n 65536
> 
> NEW login as regular user:
> 
> $ ulimit -Hn
> 65536
> $ ulimit -n
> 65536
> 
> Rob
> 
> Austad, Jay (austad at marketwatch.com) said:
> 
> > Also, I can verify this by modifying qmail so it will 
> compile without 
> > checking for this limit, and it crashes above a concurrency of 
> > anything above 509 (i.e. when the 510th qmail-remote 
> process starts).
> > 
> > > -----Original Message-----
> > > From: Austad, Jay [mailto:austad at marketwatch.com]
> > > Sent: Friday, October 19, 2001 2:40 PM
> > > To: 'tclug-list at mn-linux.org'
> > > Subject: RE: [TCLUG] FD_SET() limits in 2.4 kernel
> > > 
> > > 
> > > This doesn't work.  There is an FD_SET() limit compiled into
> > > the kernel which is set to 1024 by default.  It's been this 
> > > way for a long time.  I don't know what the difference 
> > > between fs.file-max is and the FD_SET(), but there is a 
> difference.
> > > 
> > > Jay
> > > 
> > > > -----Original Message-----
> > > > From: Rob Bajorek [mailto:rob at tatsumaki.org]
> > > > Sent: Friday, October 19, 2001 1:53 PM
> > > > To: tclug-list at mn-linux.org
> > > > Subject: Re: [TCLUG] FD_SET() limits in 2.4 kernel
> > > > 
> > > > 
> > > > Austad, Jay (austad at marketwatch.com) said:
> > > > 
> > > > > Why are the file descriptor limits still so low?  I
> > > understand that
> > > > > for most things it's fine, but when building a super high
> > > > performance
> > > > > mail server, this just isn't enough.  Can this setting be
> > > > changed on
> > > > > the fly yet like in Slowlaris?
> > > > > 
> > > > 
> > > > Look at <kernel src dir>/Documentation/filesystems/proc.txt
> > > > for info on dynamically changing fd limits.
> > > > 
> > > > or just do:
> > > > 
> > > > echo [new fd limit] > /proc/sys/fs/file-max
> > > > 
> > > > Rob
> > > > _______________________________________________
> > > > Twin Cities Linux Users Group Mailing List - Minneapolis/St.
> > > > Paul, Minnesota http://www.mn-linux.org 
> > > > tclug-list at mn-linux.org 
> > > > https://mailman.mn-> linux.org/mailman/listinfo/tclug-list
> > > > 
> > > _______________________________________________
> > > Twin Cities Linux Users Group Mailing List - Minneapolis/St.
> > > Paul, Minnesota http://www.mn-linux.org 
> > > tclug-list at mn-linux.org 
> > > https://mailman.mn-> linux.org/mailman/listinfo/tclug-list
> > > 
> > _______________________________________________
> > Twin Cities Linux Users Group Mailing List - Minneapolis/St. Paul, 
> > Minnesota http://www.mn-linux.org tclug-list at mn-linux.org
> > https://mailman.mn-linux.org/mailman/listinfo/tclug-list
> _______________________________________________
> Twin Cities Linux Users Group Mailing List - Minneapolis/St. 
> Paul, Minnesota http://www.mn-linux.org 
> tclug-list at mn-linux.org 
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