This happened after upgrading to 2.2.16. Running on Debian wheezy amd64. We never had such a crash on this server before. However, this too was a single incident. All accounts use Maildir.
Mar 21 09:32:02 imap1 dovecot: imap(----@---.com): Error: Log synchronization error at seq=0,offset=0 for /stor/mail/domains/----/----/Maildir/dovecot.index: Append with UID 6684, but next_uid = 6685 Mar 21 09:32:02 imap1 dovecot: imap(----@---.com): Error: /stor/mail/domains/----/----/Maildir/dovecot.index view syncing failed to apply changes Mar 21 09:32:02 imap1 dovecot: imap(----@---.com): Panic: file index-sync.c: line 265 (index_mailbox_sync_next_expunge): assertion failed: (range->seq2 <= ctx->messages_count) Mar 21 09:32:02 imap1 dovecot: imap(----@---.com): Error: Raw backtrace: /usr/lib/dovecot/libdovecot.so.0(+0x7b57f) [0x7f34cd27c57f] -> /usr/lib/dovecot/libdovecot.so.0(+0x7b5de) [0x7f34cd27c5de] -> /usr/lib/dovecot/libdovecot.so.0(i_fatal+0) [0x7f34cd22b0d5] -> /usr/lib/dovecot/libdovecot-storage.so.0(+0xb5391) [0x7f34cd5a6391] -> dovecot/imap ----@---.com xx.xx.xx.xx UID FETCH - 2373 bytes waiting [0x7f34cda5ad2e] -> dovecot/imap ----@---.com xx.xx.xx.xx UID FETCH - 2373 bytes waiting [0x7f34cda5b344] -> dovecot/imap ----@---.com xx.xx.xx.xx UID FETCH - 2373 bytes waiting [0x7f34cda5b67f] -> dovecot/imap ----@---.com xx.xx.xx.xx UID FETCH - 2373 bytes waiting [0x7f34cda52910] -> /usr/lib/dovecot/libdovecot.so.0(+0x98a85) [0x7f34cd299a85] -> /usr/lib/dovecot/libdovecot.so.0(io_loop_call_io+0x5b) [0x7f34cd28e80b] -> /usr/lib/dovecot/libdovecot.so.0(io_loop_handler_run_internal+0xbb) [0x7f34cd28f88b] -> /usr/lib/dovecot/libdovecot.so.0(io_loop_handler_run+0x9) [0x7f34cd28e899] -> /usr/lib/dovecot/libdovecot.so.0(io_loop_run+0x38) [0x7f34cd28e918] -> /usr/lib/dovecot/libdovecot.so.0(master_service_run+0x13) [0x7f34cd2307d3] -> dovecot/imap ----@---.com xx.xx.xx.xx UID FETCH - 2373 bytes waiting [0x7f34cda46997] -> /lib/x86_64-linux-gnu/libc.so.6(__libc_start_main+0xfd) [0x7f34cce94ead] -> dovecot/imap ----@---.com xx.xx.xx.xx UID FETCH - 2373 bytes waiting [0x7f34cda46b09] Mar 21 09:32:02 imap1 dovecot: imap(----@---.com): Fatal: master: service(imap): child 30144 killed with signal 6 (core dumps disabled)
# doveconf -n # 2.2.16: /etc/dovecot/dovecot.conf # Pigeonhole version 0.4.7 # OS: Linux 3.2.0-4-amd64 x86_64 Debian 7.8 auth_master_user_separator = * auth_mechanisms = plain login cram-md5 auth_verbose = yes auth_verbose_passwords = plain dict { expire = mysql:/etc/dovecot/dovecot-dict-sql.conf.ext quota = mysql:/etc/dovecot/dovecot-dict-sql.conf.ext } disable_plaintext_auth = no login_greeting = Dovecot ready login_log_format_elements = user=<%u> method=%m rip=%r lip=%l pip=%{real_rip} mpid=%e %c session=<%{session}> mail_gid = vmail mail_location = /nowhere mail_plugins = quota expire listescape mail_uid = vmail managesieve_sieve_capability = fileinto envelope encoded-character subaddress comparator-i;ascii-numeric relational regex imap4flags copy include variables mailbox date index ihave duplicate namespace inbox { inbox = yes location = mailbox Drafts { auto = subscribe special_use = \Drafts } mailbox Junk { auto = subscribe special_use = \Junk } mailbox Sent { auto = subscribe special_use = \Sent } mailbox "Sent Messages" { special_use = \Sent } mailbox Trash { auto = subscribe special_use = \Trash } prefix = separator = / type = private } passdb { args = /etc/dovecot/master-users driver = passwd-file master = yes pass = yes } passdb { args = /etc/dovecot/dovecot-sql.conf.ext driver = sql } plugin { antispam_backend = pipe antispam_pipe_program = /usr/bin/ssh antispam_pipe_program_args = -l;spamd;-i;/etc/dovecot/sareport.key;mx1.xxxxx antispam_pipe_program_notspam_arg = revoke antispam_pipe_program_spam_arg = report antispam_pipe_tmpdir = /tmp antispam_spam = Junk antispam_trash_pattern_ignorecase = trash;Deleted * expire = Trash expire2 = Trash/* expire3 = Junk expire_dict = proxy::expire quota = dict:user::proxy::quota quota_rule = *:storage=2G quota_rule2 = Trash:storage=+250M quota_rule3 = Junk:ignore quota_warning = storage=95%% quota-warning 95 %u quota_warning2 = storage=85%% quota-warning 85 %u sieve = ~/.dovecot.sieve sieve_before = /etc/dovecot/sieve-global/fileinto-spam.sieve sieve_dir = ~/sieve sieve_extensions = -vacation -body -reject -enotify -environment -virustest -spamtest sieve_max_actions = 32 sieve_max_redirects = 4 sieve_max_script_size = 10K sieve_quota_max_scripts = 100 sieve_quota_max_storage = 4M } pop3_no_flag_updates = yes protocols = imap pop3 lmtp sieve service auth-worker { user = $default_internal_user } service auth { client_limit = 2448 unix_listener auth-userdb { group = root mode = 0600 user = vmail } } service dict { unix_listener dict { group = root mode = 0600 user = vmail } } service imap-login { process_min_avail = 4 service_count = 0 vsz_limit = 192 M } service imap-postlogin { executable = script-login /usr/local/bin/postlogin unix_listener imap-postlogin { group = root mode = 0600 user = vmail } user = root } service imap { executable = imap imap-postlogin process_limit = 1024 vsz_limit = 128 M } service lmtp { inet_listener lmtp { address = 10.44.23.1 port = 7025 } } service managesieve-login { inet_listener sieve { port = 4190 } service_count = 0 vsz_limit = 64 M } service managesieve { process_limit = 20 } service pop3-login { process_min_avail = 4 service_count = 0 vsz_limit = 192 M } service pop3 { executable = pop3 imap-postlogin process_limit = 1024 } service quota-warning { executable = script /usr/local/bin/quota-warning unix_listener quota-warning { user = vmail } user = dovecot } ssl_cert =