Hi all, We have been running Dovecot for over a year now in our moderate volume mail environment (>4000 mailboxes) and it's been running great.

However, over the past month or so we've begun to experience issues where IMAP clients will appear to "hang" for a period of time, we then see a sig 11, and afterwards mailflow returns to normal. This usually happens a few times a day.

Naturally, our first instinct was to try and get a core dump, but after following the instructions at http://www.dovecot.org/bugreport.html we now recieve this warning:

2010-08-24T13:33:56-07:00 mail dovecot: child 9728 (login) killed with signal 11 (core not dumped - add -D to login_executable) (ip=208.98.210.13)

Adding -D to the login_executable lines didn't seem to have any effect, we are still receiving the same message. Did we perhaps misinterpret the hint?

As we've been trying for over a week now to find a way to get a dump without any success, we figured posing this to the list might help us shed some light on the issue. Any suggestions would be appreciated!

dovecot -n

1.1.20: /etc/dovecot.conf

OS: Linux 2.6.18-164.15.1.el5xen i686 CentOS release 5.5 (Final) nfs

base_dir: /var/run/dovecot/ listen: 208.98.210.10 ssl_ca_file: /etc/ssl/gd_bundle.crt ssl_cert_file: /etc/ssl/sunwave.net.crt ssl_key_file: /etc/ssl/sunwave.net.key ssl_parameters_regenerate: 1 ssl_cipher_list: ALL:!LOW verbose_ssl: yes login_dir: /var/run/dovecot//login login_executable(default): /usr/libexec/dovecot/imap-login -D login_executable(imap): /usr/libexec/dovecot/imap-login -D login_executable(pop3): /usr/libexec/dovecot/pop3-login -D mail_max_userip_connections(default): 50 mail_max_userip_connections(imap): 50 mail_max_userip_connections(pop3): 10 first_valid_uid: 200 last_valid_uid: 200 first_valid_gid: 200 last_valid_gid: 200 mail_location: maildir:/var/spool/mail/%Ld/%1Lu/%Ln/Maildir mail_debug: yes mmap_disable: yes mail_nfs_storage: yes mail_nfs_index: yes mail_executable(default): /usr/local/bin/mailtools/mail_imap.sh mail_executable(imap): /usr/local/bin/mailtools/mail_imap.sh mail_executable(pop3): /usr/local/bin/mailtools/mail_pop3.sh mail_plugins(default): quota imap_quota trash mail_plugins(imap): quota imap_quota trash mail_plugins(pop3): quota mail_plugin_dir(default): /usr/lib/dovecot/imap mail_plugin_dir(imap): /usr/lib/dovecot/imap mail_plugin_dir(pop3): /usr/lib/dovecot/pop3 namespace: type: private prefix: INBOX. inbox: yes list: yes subscriptions: yes lda: postmaster_address: do_not_reply@sunwave.net mail_plugins: quota cmusieve auth default: mechanisms: plain login default_realm: sunwave.net verbose: yes passdb: driver: sql args: /etc/dovecot-mysql.conf userdb: driver: sql args: /etc/dovecot-mysql.conf socket: type: listen client: path: /var/spool/postfix/private/auth mode: 432 user: postfix group: postfix master: path: /var/run/dovecot/auth-master mode: 511 user: vmail plugin: sieve: /var/spool/mail/%Ld/%1Lu/%Ln/Maildir/.sieve quota: maildir:Quota quota_rule2: Trash:storage=10%% quota_warning: storage=70%% /usr/local/bin/mailtools/quota-warning.sh 70 quota_warning2: storage=80%% /usr/local/bin/mailtools/quota-warning.sh 80 quota_warning3: storage=90%% /usr/local/bin/mailtools/quota-warning.sh 90 trash: /etc/dovecot-trash.conf

Thanks, Marty