Re: Help request: problems with a 5.1 server and large numbers of ssh users.

From: Peter Jeremy <PeterJeremy_at_optushome.com.au>
Date: Fri, 21 Nov 2003 18:05:22 +1100
On Wed, Nov 19, 2003 at 09:26:10PM -0800, Len Sassaman wrote:
>It is my intuition from this behavior that the sshd master process 
>listening for connections is unable to spawn a new process to complete 
>the authentication step, and thus the connection is being dropped. 
>There is no information of use in dmesg, nor in the system logs. (I've 
>cranked up LogLevel to DEBUG3 in sshd_config).

I don't have a solution but a couple of suggestions for further
investigation:

With 150 users logged in (so that no more can log in), what happens
if you start another sshd on a different port (or kill the master
sshd and start another one on port 22).

What happens if you "ktrace -i" sshd and compare the results when
the 150th client logs in to the results when the 151st client
fails to log in.  Some doctoring of PIDs with sed or similar will
allow you to diff the output without getting buried in non-differences.

I presume that the clients are attempting to connect from more than
one host (ie it's not a resource problem in the client).

Peter
Received on Thu Nov 20 2003 - 22:05:54 UTC

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