Hi,

We have a issue with a server pretty much just running dovecot, there's about 250gb of maildirs which has about 200 simultaneous connections to it running on freebsd 7. The machine has stayed up for about 8 days before it panics but sometimes panics after about 24 hours.

We are running a PAE kernel (with ULE scheduler) as the machine has 2 (4 core processors) and 8gb of ram, dovecot is compiled with kqueue support which i suspect is causing the panics. We are currently trying with a GENERIC kernel to see if this addresses the issue but looking back through the dovecot lists there seems to be some issue with kqueue, freebsd and dovecot, i am tempted to simply disable kqueue in dovecot but am not sure on the performance penalties.

Please see the freebsd pr for the kgdb dumps - for both dumps the current process was imap, and the second one seemed to hint towards a problem with kqueue but im not a c or kernel hacker:

http://www.freebsd.org/cgi/query-pr.cgi?pr=129550

--- snip of what i think is relevent from the dump ---

(kgdb) list *0xc04c4c4d 0xc04c4c4d is in knlist_remove_kq (/usr/src/sys/kern/kern_event.c:1615). 1610 if (!kqislocked) 1611 KASSERT((kn->kn_status & (KN_INFLUX|KN_DETACHED)) == KN_INFLUX, 1612 ("knlist_remove called w/o knote being KN_INFLUX or already removed")); 1613 if (!knlislocked) 1614 knl->kl_lock(knl->kl_lockarg); 1615 SLIST_REMOVE(&knl->kl_list, kn, knote, kn_selnext); 1616 kn->kn_knlist = NULL; 1617 if (!knlislocked) 1618 knl->kl_unlock(knl->kl_lockarg); 1619 if (!kqislocked) (kgdb)

mail# dovecot -n # 1.1.7: /usr/local/etc/dovecot.conf # OS: FreeBSD 7.0-RELEASE-p6 i386 ssl_cert_file: /etc/ssl/dovecot.pem ssl_key_file: /etc/ssl/dovecot.pem login_dir: /var/run/dovecot/login login_executable: /usr/local/libexec/dovecot/imap-login login_process_per_connection: no login_processes_count: 20 login_max_processes_count: 256 login_max_connections: 512 max_mail_processes: 1024 verbose_proctitle: yes first_valid_uid: 89 last_valid_uid: 89 first_valid_gid: 89 last_valid_gid: 89 mail_privileged_group: mail imap_client_workarounds: delay-newmail outlook-idle netscape-eoh tb-extra-mailbox-sep auth default: passdb: driver: vpopmail userdb: driver: vpopmail