dovecot - May 2009 - dovecot: child xxxx (login) returned error 83 (Out of memory)

Hi,

Recently started receiving the error $SUBJECT.  Soon after a number of
segfault errors are reported for pop3-login.  Based on my configuration, I
believe I am set up to receive core files; however, my  ulimit -c is 0.  I
have tried setting ulimit -c ... in /etc/init.d/dovecot and I have tried
modifying /etc/security/limits.conf.  In all cases /proc/[pid]/limits
continued to report that my ulimit -c value was 0.  What is the best process
for capturing a core file from a login process (pop3-login).

I have found some similar hits on the web for this; however, none appear to
lead to resolution and in most cases the implementation includes imap,
mysql, etc...

Here is my dovecot.conf, any insight into the cause of this problem is
greatly appreciated.  Dovecot package is that shipped with RHEL 5.2
(dovecot-1.0.7-2.el5).

<dovecot.conf>
protocols = pop3 pop3s
listen = *
shutdown_clients = yes

#log_path = /var/log/pop.log
#info_log_path = /var/log/popinfo.log
syslog_facility = local6

ssl_disable = no

ssl_cert_file = /etc/pki/dovecot/certs/pop.pem
ssl_key_file = /etc/pki/dovecot/private/pop.pem

login_dir = /var/run/dovecot/login
login_user = dovecot
login_process_size = 64
login_process_per_connection = no
login_processes_count = 3
login_max_connections = 512
login_max_processes_count = 512
max_mail_processes = 10000
login_greeting = Unauthorized access is prohibited.

mail_location = mbox:/var/indexes/%u:INBOX=/var/spool/mail/%u

mail_privileged_group = vmail

pop3_lock_session = yes
######added for perfomance 61208 MT (Just for testing)
# test with and without the following
pop3_no_flag_updates = yes
mmap_disable = yes
mbox_read_locks = fcntl
mbox_write_locks = fcntl
mbox_lock_timeout = 300
#mbox_dirty_syncs = yes
mbox_very_dirty_syncs = yes
mbox_lazy_writes = yes
mbox_min_index_size = 540

protocol imap {
}

protocol pop3 {
 pop3_uidl_format = %08Xv%08Xu
}

protocol lda {
 postmaster_address = postmaster at example.com
}

auth default {

  auth_cache_size = 10240
  auth_cache_ttl = 18000
  auth_debug=no
  mechanisms = plain
    passdb ldap {
       args = /etc/dovecot-ldap.conf
                }
    userdb ldap {
       args = /etc/dovecot-ldap.conf
                }
  auth_verbose = no

           }

dict {
}

plugin {
}

###  The following added to troubleshoot segfault issue 6.16.08 by rt
mail_drop_priv_before_exec = yes
</dovecot.conf>

On May 28, 2009, at 6:11 PM, Eric Sammons wrote:
> Recently started receiving the error $SUBJECT.  Soon after a number of
> segfault errors are reported for pop3-login.  Based on my  
> configuration, I
> believe I am set up to receive core files; however, my  ulimit -c is  
> 0.
You won't get core dumps from login processes, because the kernel  
treats them as setuid-processes and also their current directory isn't  
writable. With recent versions you could add -D parameter to make this  
happen.
> Here is my dovecot.conf, any insight into the cause of this problem is
> greatly appreciated.
> login_process_size = 64
Increase this and the problem goes away.