Did you already solve this? If not, just mail the strace output to me privately and I'll take a look at it.

On Fri, 2009-01-30 at 09:39 -0300, Mauricio López Riffo wrote:

Timo,

What messages should be see? I execute the commands and shows a lot of messages, i dont know what it means, i m not a programmer :)

Thanks

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Mauricio López Riffo Red Hat Certified Engineer 804006455319519 Netline Telecomunicaciones Chile Los Conquistadores 2430, Providencia, Santiago. Codigo Postal: 7530041 Fono: +562 6560600 Móvil: +569 90992366

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-----Mensaje original----- De: Timo Sirainen [mailto:tss@iki.fi] Enviado el: jueves, 29 de enero de 2009 20:46 Para: mauricio.lopez@netline.net; Dovecot Mailing List Asunto: Re: [Dovecot] Concurrent POP3 Sessions Issues

On Jan 29, 2009, at 1:17 PM, Mauricio López Riffo wrote:

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I have problems with dovecot + ldap + nfs, we could't have more than 20 concurrent sessions of pop3, when user 21 comes, the auth process takes more than 1 sec and is incresing (while most users arrives, more delay in autenticacion exists) and my customers complaint about the service. We need support about 200 concurrents pop3 users, here is my details

Someone else was recently complaining about the same thing. Or was it you? Anyway, dovecot-auth doesn't know how many users are logged in so if the problem really is 21 *concurrent users* instead of n logins/ second, I find it highly unlikely that the problem is with authentication.

My guess is that this has something to do with NFS. Perhaps start Dovecot with strace -tt -f dovecot and then when it's slowing down see what syscall it says is blocking.