Hello.

We are running dovecot 2.0.13 with mdbox+zlib on RHEL 5.7 x64, ext4. We use NTP. Indexes are in a iSCSI raid 10, mailboxes in raid5. No NFS. We have detected that sometimes all users get disconnected from roundcube at the same time. In dovecot logs we hundreds of lines like this:

Nov 3 09:23:07 buzon dovecot: imap(mcrivero@mydomain): Warning: Created dotlock file's timestamp is different than current time (1320308587 vs 1320308542): /buzones/mydomain/03/67/mcrivero/subscriptions Nov 3 09:23:07 buzon dovecot: imap(mcrivero@mydomain): Connection closed bytes=0/295 Nov 3 09:23:07 buzon dovecot: imap(delolmo@mydomain): Warning: Created dotlock file's timestamp is different than current time (1320308587 vs 1320308542): /buzones/mydomain/15/77/delolmo/subscriptions Nov 3 09:23:07 buzon dovecot: imap(delolmo@mydomain): Connection closed bytes=0/295

I have been googling but I only see problems with remote NFS, our setup does not use NFS. I give you doveconf -n output & mount options, if more info es needed, please ask.

doveconf -n output

# 2.0.13: /etc/dovecot/dovecot.conf # OS: Linux 2.6.18-274.el5 x86_64 Red Hat Enterprise Linux Server release 5.7 (Tikanga) ext4 auth_cache_negative_ttl = 10 secs auth_cache_size = 10 M auth_cache_ttl = 2 mins auth_master_user_separator = * auth_mechanisms = plain login auth_worker_max_count = 3500 base_dir = /var/run/dovecot/ default_client_limit = 5000 default_process_limit = 6500 disable_plaintext_auth = no imap_client_workarounds = tb-extra-mailbox-sep delay-newmail tb-lsub-flags lda_mailbox_autocreate = yes lda_mailbox_autosubscribe = yes mail_fsync = never mail_gid = entrega mail_home = /buzones/mydomain/%2.26Hn/%2.200Hn/%n/home_usuario/ mail_location = mdbox:/buzones/mydomain/%2.26Hn/%2.200Hn/%n:INDEX=/indices_dovecot/indices/%2.26Hn/%2.200Hn/%n mail_max_userip_connections = 15000 mail_plugins = " zlib acl quota autocreate" mail_uid = entrega managesieve_notify_capability = mailto managesieve_sieve_capability = fileinto reject envelope encoded-character vacation subaddress comparator-i;ascii-numeric relational regex imap4flags copy include variables body enotify environment mailbox date mdbox_rotate_interval = 1 days mdbox_rotate_size = 60 M passdb { args = /etc/dovecot/dovecot-ldap.conf driver = ldap } passdb { args = /etc/usuario_maestro.txt driver = passwd-file master = yes } passdb { args = /etc/dovecot/dovecot-ldap.conf driver = ldap } plugin { acl = vfile autocreate = SPAM autocreate2 = Sent autocreate3 = Drafts autocreate4 = Trash autosubscribe = SPAM autosubscribe2 = Sent autosubscribe3 = Drafts autosubscribe4 = Trash lda_mailbox_autosubscribe = yes quota = dict:Cuota de usuario::file:/buzones/cuotas/%n quota_rule2 = Trash:storage=+10%% quota_warning = storage=90%% aviso_cuota 90 %u sieve = /buzones/mydomain/%2.26Hn/%2.200Hn/%n/home_usuario/dovecot.sieve sieve_dir = /buzones/mydomain/%2.26Hn/%2.200Hn/%n/home_usuario/sieve/ zlib_save = gz zlib_save_level = 9 } pop3_no_flag_updates = yes protocols = pop3 imap sieve service anvil { client_limit = 25000 } service auth { client_limit = 28000 unix_listener auth-master { user = entrega } unix_listener auth-userdb { user = entrega } user = root } service aviso_cuota { executable = script /usr/local/bin/quota-warning.sh unix_listener aviso_cuota { mode = 0666 } user = entrega } service imap-login { executable = /usr/libexec/dovecot/imap-login group = dovenull service_count = 0 } service imap { executable = /usr/libexec/dovecot/imap process_limit = 6000 } service managesieve-login { executable = /usr/libexec/dovecot/managesieve-login inet_listener sieve { port = 2000 } process_limit = 2000 } service managesieve { executable = /usr/libexec/dovecot/managesieve process_limit = 5000 } service pop3-login { executable = /usr/libexec/dovecot/pop3-login process_limit = 4000 service_count = 0 } service pop3 { executable = /usr/libexec/dovecot/pop3 process_limit = 4000 } ssl_ca =

mount points:

/dev/mapper/Volumen_0-Logico_0 on / type ext3 (rw) proc on /proc type proc (rw) sysfs on /sys type sysfs (rw) devpts on /dev/pts type devpts (rw,gid=5,mode=620) /dev/sda1 on /boot type ext3 (rw) tmpfs on /dev/shm type tmpfs (rw) none on /proc/sys/fs/binfmt_misc type binfmt_misc (rw) sunrpc on /var/lib/nfs/rpc_pipefs type rpc_pipefs (rw) /dev/mapper/Buzon_mydomain-buzones on /buzones type ext4 (rw,noatime,nodiratime,nobarrier,commit=15,data=writeback)

Indexes are located somewhere in "/" mount point.