[Dovecot] FreeBSD, Dovecot and ZFS

[Jason Lock]

>> WAG would be similar issues you can face when using NFS with multiple servers accessing it (file locking issues).
>> The solution would be to use Director to make sure users are always directed to the same server.
>> http://wiki2.dovecot.org/Director
>> If that isn't the problem, then much more info would be needed (ie, doveconf -n output, logs exhibiting the problem, etc)...
>> -- 
>>
>> Best regards,
>>
>> */Charles /*

Thank you for your reply.  To further expand the problem does not happen with any regularity, we went over 30 days with no issue after two weeks of sporadic occurrences.  It usually only appears, if at all, any time after 2:00 PM (i.e. 14:30, 15:20, 16:10).  And not every day (has not happened on a weekend).  The number of POP3 and IMAP processes increase dramatically when the issue occurs.

Here is a copy of the dovecot -n output

# 1.2.17: /usr/local/etc/dovecot.conf
# OS: FreeBSD 8.1-RELEASE-p5 i386  nfs
protocols: imap imaps pop3 pop3s
ssl_cert_file: /mail/shared/etc/ssl/certs/dovecot.pem
ssl_key_file: /mail/shared/etc/ssl/private/dovecot.pem
disable_plaintext_auth: no
login_dir: /var/run/dovecot/login
login_executable(default): /usr/local/libexec/dovecot/imap-login
login_executable(imap): /usr/local/libexec/dovecot/imap-login
login_executable(pop3): /usr/local/libexec/dovecot/pop3-login
login_greeting: Hello there, who might you be?
max_mail_processes: 4096
verbose_proctitle: yes
first_valid_uid: 26
first_valid_gid: 0
mail_privileged_group: mail
mail_location: maildir:/mail/store/%d/%n
mmap_disable: yes
dotlock_use_excl: no
mail_nfs_storage: yes
mail_nfs_index: yes
lock_method: dotlock
mail_executable(default): /usr/local/libexec/dovecot/imap
mail_executable(imap): /usr/local/libexec/dovecot/imap
mail_executable(pop3): /usr/local/libexec/dovecot/pop3
mail_plugin_dir(default): /usr/local/lib/dovecot/imap
mail_plugin_dir(imap): /usr/local/lib/dovecot/imap
mail_plugin_dir(pop3): /usr/local/lib/dovecot/pop3
imap_client_workarounds(default): delay-newmail outlook-idle netscape-eoh tb-extra-mailbox-sep
imap_client_workarounds(imap): delay-newmail outlook-idle netscape-eoh tb-extra-mailbox-sep
imap_client_workarounds(pop3):
pop3_client_workarounds(default):
pop3_client_workarounds(imap):
pop3_client_workarounds(pop3): outlook-no-nuls oe-ns-eoh
lda:
  postmaster_address: {REMOVED}
  sendmail_path: /usr/local/sbin/exim
auth default:
  default_realm: {REMOVED}
  username_format: %Lu
  passdb:
    driver: sql
    args: /mail/shared/etc/dovecot-sql.conf
  userdb:
    driver: passwd
  userdb:
    driver: static
    args: uid=26 gid=6 home=/mail/store/%d/%n