We have started seeing index corruption ever since we upgraded (we believe) our imap servers from SL6 to Centos 7. Mail/Indexes are stored on Netapps mounted via NFS. We have 2 lvs servers running surealived in dr/wlc, 2 directors and 6 backend imap/pop servers.

Most of the core dumps I've looked at for different users are like "Backtrace 2" with some variations on folder path.

This latest crash (Backtrace 1) is different from others I've seen. It is also leaving 0byte files in the users .Drafts/tmp folder.

# ls -s /var/spool/mail/15/00/user1/.Drafts/tmp | awk '{print $1}'
|sort | uniq -c 9692 0 1 218600

I believe the number of cores here is different from the number of tmp files because this is when we moved the user to our debug server so we could get the core dumps. # ls -la /home/u/user1/core.* |wc -l
8437

Any help/insight would be greatly appreciated.

Thanks, William

OS Info: CentOS Linux release 7.5.1804 (Core) 3.10.0-862.14.4.el7.x86_64

NFS: # mount -t nfs |grep mail/15 172.16.255.14:/vol/vol1/mail/15 on /var/spool/mail/15 type nfs (rw,nosuid,nodev,relatime,vers=3,rsize=32768,wsize=32768,namlen=255,hard,nordirplus,proto=tcp,timeo=600,retrans=2,sec=sys,mountaddr=172.16.255.14,mountvers=3,mountport=4046,mountproto=udp,local_lock=none,addr=172.16.255.14)

Dovecot Info: dovecot -n # 2.1.17: /etc/dovecot/dovecot.conf # OS: Linux 3.10.0-862.14.4.el7.x86_64 x86_64 CentOS Linux release 7.5.1804 (Core) auth_failure_delay = 0 auth_master_user_separator = * auth_username_format = %Ln auth_verbose = yes auth_verbose_passwords = sha1 auth_worker_max_count = 64 login_log_format_elements = user=<%u> session=%{session} method=%m rip=%r lip=%l mpid=%e %c login_trusted_networks = 172.16.0/24 mail_debug = yes mail_fsync = always mail_log_prefix = "%s(%u): session=%{session} " mail_plugins = zlib maildir_very_dirty_syncs = yes mmap_disable = yes passdb { args = /etc/dovecot/master-users driver = passwd-file master = yes } passdb { args = imap driver = pam } plugin { lazy_expunge = DELETED_MESSAGES. mail_log_events = delete expunge flag_change mail_log_fields = uid box msgid from flags size quota = fs:User quota stats_refresh = 30 secs stats_track_cmds = yes } protocols = imap pop3 service anvil { client_limit = 10000 } service auth { client_limit = 10000 vsz_limit = 1 G } service doveadm { inet_listener { port = 1842 } unix_listener doveadm-server { mode = 0666 } } service imap-login { inet_listener imap { port = 143 } inet_listener imaps { port = 993 ssl = yes } process_limit = 7000 process_min_avail = 32 vsz_limit = 256 M } service imap-postlogin { executable = script-login -d /etc/dovecot/bin/foo-imap-postlogin user = $default_internal_user } service imap { executable = imap imap-postlogin process_limit = 7000 vsz_limit = 1492 M } service pop3-login { inet_listener pop3 { port = 110 } inet_listener pop3s { port = 995 ssl = yes } process_limit = 2000 process_min_avail = 32 vsz_limit = 256 M } service pop3-postlogin { executable = script-login -d /etc/dovecot/bin/foo-pop3-postlogin user = $default_internal_user } service pop3 { executable = pop3 pop3-postlogin process_limit = 2000 } shutdown_clients = no ssl = required ssl_ca = </etc/dovecot/ssl/imap.foo.com.ca-bundle ssl_cert = </etc/dovecot/ssl/imap.foo.com.crt ssl_key = </etc/dovecot/ssl/imap.foo.com.key ssl_parameters_regenerate = 1 days ssl_protocols = !SSLv2 !SSLv3 syslog_facility = local0 userdb { driver = passwd } verbose_proctitle = yes protocol imap { imap_id_send = support-url support-email imap_max_line_length = 128 k mail_max_userip_connections = 20 mail_plugins = zlib mail_log notify imap_zlib ssl_ca = </etc/dovecot/ssl/imap.foo.com.ca-bundle ssl_cert = </etc/dovecot/ssl/imap.foo.com.crt ssl_key = </etc/dovecot/ssl/imap.foo.com.key } protocol pop3 { mail_plugins = zlib lazy_expunge pop3_fast_size_lookups = yes pop3_uidl_format = %f ssl_ca = </etc/dovecot/ssl/pop.foo.com.ca-bundle ssl_cert = </etc/dovecot/ssl/pop.foo.com.crt ssl_key = </etc/dovecot/ssl/pop.foo.com.key }

Backtrace 1: Reading symbols from /usr/libexec/dovecot/imap...Reading symbols from /usr/lib/debug/usr/libexec/dovecot/imap.debug...done. Program terminated with signal 6, Aborted. #0 0x00007fbee47e0277 in __GI_raise (sig=sig@entry=6) at ../nptl/sysdeps/unix/sysv/linux/raise.c:56 56 return INLINE_SYSCALL (tgkill, 3, pid, selftid, sig);

Thread 1 (Thread 0x7fbee532f840 (LWP 9449)): #0 0x00007fbee47e0277 in __GI_raise (sig=sig@entry=6) at ../nptl/sysdeps/unix/sysv/linux/raise.c:56 resultvar = 0 pid = 9449 selftid = 9449 #1 0x00007fbee47e1968 in __GI_abort () at abort.c:90 save_stage = 2 act = {__sigaction_handler = {sa_handler = 0x0, sa_sigaction = 0x0}, sa_mask = {__val = {0 <repeats 11 times>, 31683224, 140725444114256, 31908720, 140457858143945, 31683224}}, sa_flags = -457466710, sa_restorer = 0x0} sigs = {__val = {32, 0 <repeats 15 times>}} #2 0x00007fbee4bbdb65 in default_fatal_finish (type=<optimized out>, status=status@entry=0) at failures.c:191 backtrace = 0x1e372d0 "/usr/lib64/dovecot/libdovecot.so.0(+0x46b55) [0x7fbee4bbdb55] -> /usr/lib64/dovecot/libdovecot.so.0(+0x46c1e) [0x7fbee4bbdc1e] -> /usr/lib64/dovecot/libdovecot.so.0(i_fatal+0) [0x7fbee4b90dda] -> /usr"... #3 0x00007fbee4bbdc1e in i_internal_fatal_handler (ctx=0x7ffd321b77a0, format=<optimized out>, args=<optimized out>) at failures.c:649 status = 0 #4 0x00007fbee4b90dda in i_panic (format=format@entry=0x7fbee4ee0588 "file %s: line %d (%s): assertion failed: (%s)") at failures.c:263 ctx = {type = LOG_TYPE_PANIC, exit_status = 0, timestamp = 0x0} args = {{gp_offset = 40, fp_offset = 48, overflow_arg_area = 0x7ffd321b7890, reg_save_area = 0x7ffd321b77d0}} #5 0x00007fbee4ea96ad in index_mail_parse_body_finish (mail=0x1e69570, field=field@entry=MAIL_CACHE_FLAGS) at index-mail.c:769 parser_input = 0x1e6e370 ret = 1 __FUNCTION__ = "index_mail_parse_body_finish" #6 0x00007fbee4eaaa2b in index_mail_cache_parse_deinit (_mail=<optimized out>, received_date=<optimized out>, success=<optimized out>) at index-mail.c:1624 mail = <optimized out> #7 0x00007fbee4e5dce3 in maildir_save_finish_real (_ctx=0x1e68560) at maildir-save.c:551 ctx = 0x1e68560 e = 0x1e574d0 output_errno = <optimized out> path = 0x1e37218 "/var/spool/mail/15/00/user1/.Drafts/tmp/1539107164.M157986P9449.debug.imapd.foo.com" real_size = <optimized out> size = 1539107194 #8 maildir_save_finish (ctx=0x1e68560) at maildir-save.c:630 _data_stack_cur_id = 3 #9 0x00007fbee4e90ce6 in mailbox_save_cancel (_ctx=_ctx@entry=0x1e58d58) at mail-storage.c:1697 ctx = 0x1e68560 keywords = 0x1e65860 mail = <optimized out> #10 0x0000000000409459 in cmd_append_continue_message (cmd=0x1e58c10) at cmd-append.c:420 client = 0x1e58070 ctx = 0x1e58d10 size = 31819840 ret = 3920 #11 0x000000000041186c in command_exec (cmd=0x1e58c10) at imap-commands.c:148 hook = 0x1e40d00 ret = <optimized out> #12 0x0000000000408d21 in client_input_append (cmd=0x1e58c10) at cmd-append.c:101 ctx = 0x1e58d10 client = 0x1e58070 finished = <optimized out> __FUNCTION__ = "client_input_append" #13 0x00007fbee4bcaaa7 in io_loop_call_io (io=0x1e58b10) at ioloop.c:379 ioloop = 0x1e3f6a0 t_id = 2 #14 0x00007fbee4bcb857 in io_loop_handler_run (ioloop=ioloop@entry=0x1e3f6a0) at ioloop-epoll.c:213 ctx = 0x1e3fa10 events = <optimized out> list = 0x1e58b60 io = <optimized out> tv = {tv_sec = 1799, tv_usec = 999445} events_count = <optimized out> msecs = <optimized out> ret = 1 i = 0 call = <optimized out> #15 0x00007fbee4bca628 in io_loop_run (ioloop=0x1e3f6a0) at ioloop.c:398 No locals. #16 0x00007fbee4bb6213 in master_service_run (service=0x1e3f550, callback=callback@entry=0x418fb0 <client_connected>) at master-service.c:544 No locals. #17 0x0000000000408933 in main (argc=2, argv=0x1e3f390) at main.c:389 set_roots = {0x41c320 <imap_setting_parser_info>, 0x0} login_set = {auth_socket_path = 0x1e37090 "/run/dovecot/auth-master", postlogin_socket_path = 0x1e370c0 "/run/dovecot/imap-postlogin", postlogin_timeout_secs = 60, callback = 0x419440 <login_client_connected>, failure_callback = 0x419150 <login_client_failed>} service_flags = <optimized out> storage_service_flags = <optimized out> username = 0x0 c = <optimized out>

Backtrace 2: Reading symbols from /usr/libexec/dovecot/imap...Reading symbols from /usr/lib/debug/usr/libexec/dovecot/imap.debug...done. Program terminated with signal 6, Aborted. #0 0x00007f437288c277 in __GI_raise (sig=sig@entry=6) at ../nptl/sysdeps/unix/sysv/linux/raise.c:56 56 return INLINE_SYSCALL (tgkill, 3, pid, selftid, sig);

Thread 1 (Thread 0x7f43733d3840 (LWP 6725)): #0 0x00007f437288c277 in __GI_raise (sig=sig@entry=6) at ../nptl/sysdeps/unix/sysv/linux/raise.c:56 resultvar = 0 pid = 6725 selftid = 6725 #1 0x00007f437288d968 in __GI_abort () at abort.c:90 save_stage = 2 act = {__sigaction_handler = {sa_handler = 0x0, sa_sigaction = 0x0}, sa_mask = {__val = {0 <repeats 11 times>, 19630744, 140729812750864, 1, 139927665268057, 19630744}}, sa_flags = 1925602218, sa_restorer = 0x0} sigs = {__val = {32, 0 <repeats 15 times>}} #2 0x00007f4372c69a25 in default_fatal_finish (type=<optimized out>, status=status@entry=0) at failures.c:191 backtrace = 0x12b8ad0 "/usr/lib64/dovecot/libdovecot.so.0(+0x46a15) [0x7f4372c69a15] -> /usr/lib64/dovecot/libdovecot.so.0(+0x46ade) [0x7f4372c69ade] -> /usr/lib64/dovecot/libdovecot.so.0(i_fatal+0) [0x7f4372c3cdaa] -> /usr"... #3 0x00007f4372c69ade in i_internal_fatal_handler (ctx=0x7ffe367f9260, format=<optimized out>, args=<optimized out>) at failures.c:649 status = 0 #4 0x00007f4372c3cdaa in i_panic (format=format@entry=0x7f4372f83cc8 "file %s: line %d (%s): assertion failed: (%s)") at failures.c:263 ctx = {type = LOG_TYPE_PANIC, exit_status = 0, timestamp = 0x0} args = {{gp_offset = 40, fp_offset = 48, overflow_arg_area = 0x7ffe367f9350, reg_save_area = 0x7ffe367f9290}} #5 0x00007f4372f77eb8 in keywords_update_records (ext=0x13827e8, ext=0x13827e8, uid2=<optimized out>, uid1=<optimized out>, type=MODIFY_ADD, keyword_idx=0, ctx=0x7ffe367f94e0) at mail-index-sync-keywords.c:228 data = <optimized out> data_mask = 1 '\001' seq1 = 346 view = 0x134c110 rec = <optimized out> data_offset = <optimized out> seq2 = 346 #6 mail_index_sync_keywords (ctx=ctx@entry=0x7ffe367f94e0, hdr=hdr@entry=0x1345bb8, rec=rec@entry=0x13a54e4) at mail-index-sync-keywords.c:304 view = <optimized out> keyword_name = <optimized out> ext = 0x13827e8 uid = <optimized out> end = 0x13a54fc seqset_offset = <optimized out> ext_map_idx = 2 keyword_idx = 0 __FUNCTION__ = "mail_index_sync_keywords" #7 0x00007f4372f78822 in mail_index_sync_record_real (data=0x13a54e4, hdr=0x1345bb8, ctx=0x7ffe367f94e0) at mail-index-sync-update.c:779 rec = 0x13a54e4 ret = 0 #8 mail_index_sync_record (ctx=ctx@entry=0x7ffe367f94e0, hdr=0x1345bb8, data=0x13a54e4) at mail-index-sync-update.c:824 _data_stack_cur_id = 7 ret = 0 #9 0x00007f4372f79866 in mail_index_sync_map (_map=_map@entry=0x1346498, type=type@entry=MAIL_INDEX_SYNC_HANDLER_HEAD, force=force@entry=true) at mail-index-sync-update.c:1036 map = <optimized out> index = 0x1346410 view = 0x134c110 sync_map_ctx = {view = 0x134c110, modseq_ctx = 0x138d330, cur_ext_map_idx = 0, ext_intro_seq = 105, ext_intro_offset = 13792, ext_intro_end_offset = 13820, expunge_handlers = {arr = {buffer = 0x0, element_size = 0}, v = 0x0, v_modifiable = 0x0}, extra_contexts = { arr = {buffer = 0x134d8c0, element_size = 8}, v = 0x134d8c0, v_modifiable = 0x134d8c0}, unknown_extensions = 0x0, type = MAIL_INDEX_SYNC_HANDLER_HEAD, sync_handlers_initialized = 0, expunge_handlers_set = 0, expunge_handlers_used = 0, cur_ext_ignore = 0, internal_update = 0, errors = 0} thdr = 0x1345bb8 tdata = 0x13a54e4 prev_seq = 105 start_offset = <optimized out> prev_offset = 14084 ret = <optimized out> had_dirty = <optimized out> reset = false __FUNCTION__ = "mail_index_sync_map" #10 0x00007f4372f6a6e4 in mail_index_map (index=index@entry=0x1346410, type=type@entry=MAIL_INDEX_SYNC_HANDLER_HEAD) at mail-index-map-read.c:433 ret = <optimized out> __FUNCTION__ = "mail_index_map" #11 0x00007f4372f65a90 in mail_index_try_open (index=index@entry=0x1346410) at mail-index.c:426 ret = <optimized out> __FUNCTION__ = "mail_index_try_open" #12 0x00007f4372f66130 in mail_index_open_files (index=index@entry=0x1346410, flags=flags@entry=(MAIL_INDEX_OPEN_FLAG_CREATE | MAIL_INDEX_OPEN_FLAG_MMAP_DISABLE | MAIL_INDEX_OPEN_FLAG_DOTLOCK_USE_EXCL)) at mail-index.c:504 ret = <optimized out> created = false #13 0x00007f4372f66230 in mail_index_open (index=0x1346410, flags=flags@entry=(MAIL_INDEX_OPEN_FLAG_CREATE | MAIL_INDEX_OPEN_FLAG_MMAP_DISABLE | MAIL_INDEX_OPEN_FLAG_DOTLOCK_USE_EXCL)) at mail-index.c:594 ret = <optimized out> __FUNCTION__ = "mail_index_open" #14 0x00007f4372f57a17 in index_storage_mailbox_open (box=box@entry=0x1388750, move_to_memory=move_to_memory@entry=false) at index-storage.c:231 ibox = 0x1388b48 index_flags = (MAIL_INDEX_OPEN_FLAG_CREATE | MAIL_INDEX_OPEN_FLAG_MMAP_DISABLE | MAIL_INDEX_OPEN_FLAG_DOTLOCK_USE_EXCL) ret = <optimized out> __FUNCTION__ = "index_storage_mailbox_open" #15 0x00007f4372f03212 in maildir_mailbox_open_existing (box=box@entry=0x1388750) at maildir-storage.c:305 mbox = 0x1388750 #16 0x00007f4372f03960 in maildir_mailbox_open (box=0x1388750) at maildir-storage.c:365 box_path = 0x1388f68 "/var/spool/mail/16/47/user2/DELETED_MESSAGES/.INBOX" root_dir = <optimized out> st = {st_dev = 140729812752383, st_ino = 140729812752416, st_nlink = 19629048, st_mode = 914331680, st_uid = 32766, st_gid = 4300439, __pad0 = 0, st_rdev = 140729812752896, st_size = 1, st_blksize = 133, st_blocks = 19629048, st_atim = {tv_sec = 139927662018357, tv_nsec = 4222451713}, st_mtim = {tv_sec = 139927664838496, tv_nsec = 139927664838496}, st_ctim = {tv_sec = 344592, tv_nsec = -140729812752575}, __unused = {129, 32, 4}} ret = <optimized out> #17 0x00007f436fd13942 in zlib_mailbox_open (box=0x1388750) at zlib-plugin.c:346 zbox = 0x1388e30 #18 0x00007f4372f34cc7 in mailbox_open_full (box=0x1388750, input=0x0) at mail-storage.c:907 _data_stack_cur_id = 6 ret = <optimized out> input = 0x0 box = 0x1388750 #19 0x00007f4372f35070 in mailbox_open (box=box@entry=0x1388750) at mail-storage.c:942 No locals. #20 0x00007f4372f56b2b in index_storage_get_status (box=0x1388750, items=STATUS_UNSEEN, status_r=0x7ffe367f9b40) at index-status.c:41 hdr = <optimized out> __FUNCTION__ = "index_storage_get_status" #21 0x00000000004175f5 in imap_status_get (cmd=0x12d99b0, ns=0x12d8590, mailbox=mailbox@entry=0x13883e0 "DELETED_MESSAGES.INBOX", items=items@entry=0x12d9aec, result_r=result_r@entry=0x7ffe367f9b40, error_r=error_r@entry=0x7ffe367f9b38) at imap-status.c:84 client = 0x12d8e60 box = 0x1388750 error = MAIL_ERROR_NONE ret = 0 #22 0x000000000040bee7 in list_send_status (flags=<optimized out>, mutf7_name=0x12b8548 "DELETED_MESSAGES.INBOX", name=0x13883e0 "DELETED_MESSAGES.INBOX", ctx=0x12d9ad0) at cmd-list.c:466 result = {status = {messages = 0, recent = 0, unseen = 0, uidvalidity = 0, uidnext = 0, first_unseen_seq = 0, first_recent_uid = 0, last_cached_seq = 0, highest_modseq = 0, keywords = 0x0, permanent_flags = 0, nonpermanent_modseqs = 0, permanent_keywords = 0, allow_new_keywords = 0}, metadata = {guid = '\000' <repeats 15 times>, virtual_size = 0, cache_fields = 0x0, precache_fields = (MAIL_FETCH_DATE | MAIL_FETCH_RECEIVED_DATE | MAIL_FETCH_SAVE_DATE | MAIL_FETCH_VIRTUAL_SIZE | MAIL_FETCH_NUL_STATE | MAIL_FETCH_IMAP_BODY | MAIL_FETCH_FROM_ENVELOPE | MAIL_FETCH_HEADER_MD5 | MAIL_FETCH_UIDL_BACKEND | MAIL_FETCH_MAILBOX_NAME | MAIL_FETCH_GUID | unknown: 16779264)}} ns = <optimized out> error = 0x12b8360 "*" #23 list_namespace_mailboxes (ctx=0x12d9ad0) at cmd-list.c:566 _data_stack_cur_id = 5 info = <optimized out> flags = <optimized out> str = 0x12b83c0 ret = 1 ns = 0x0 mutf7_name = 0x12b8510 name = 0x13883e0 "DELETED_MESSAGES.INBOX" #24 cmd_list_continue (cmd=cmd@entry=0x12d99b0) at cmd-list.c:912 _data_stack_cur_id = 4 ctx = 0x12d9ad0 #25 0x000000000040cb27 in cmd_list_full (cmd=0x12d99b0, lsub=<optimized out>) at cmd-list.c:1092 client = 0x12d8e60 args = 0x12c3968 list_args = 0x12c3a40 arg_count = 0 ctx = 0x12d9ad0 patterns = {arr = {buffer = <optimized out>, element_size = 8}, v = <optimized out>, v_modifiable = <optimized out>} pattern = 0x12b8360 "*" patterns_strarr = <optimized out> str = <optimized out> #26 0x00000000004117fc in command_exec (cmd=cmd@entry=0x12d99b0) at imap-commands.c:148 hook = 0x12c1d00 ret = <optimized out> #27 0x000000000041079b in client_command_input (cmd=cmd@entry=0x12d99b0) at imap-client.c:682 client = 0x12d8e60 command = <optimized out> __FUNCTION__ = "client_command_input" #28 0x0000000000410885 in client_command_input (cmd=0x12d99b0) at imap-client.c:733 client = 0x12d8e60 command = <optimized out> __FUNCTION__ = "client_command_input" #29 0x0000000000410aed in client_handle_next_command (remove_io_r=<synthetic pointer>, client=0x12d8e60) at imap-client.c:774 size = 52 #30 client_handle_input (client=client@entry=0x12d8e60) at imap-client.c:786 _data_stack_cur_id = 3 remove_io = false handled_commands = false __FUNCTION__ = "client_handle_input" #31 0x0000000000411302 in client_input (client=0x12d8e60) at imap-client.c:825 cmd = 0x7f4372c69eae <i_set_failure_prefix+46> output = 0x12dde18 bytes = 52 __FUNCTION__ = "client_input" #32 0x00007f4372c76937 in io_loop_call_io (io=0x12d1150) at ioloop.c:379 ioloop = 0x12c06a0 t_id = 2 #33 0x00007f4372c776e7 in io_loop_handler_run (ioloop=ioloop@entry=0x12c06a0) at ioloop-epoll.c:213 ctx = 0x12c0a10 events = <optimized out> list = 0x12d9900 io = <optimized out> tv = {tv_sec = 1799, tv_usec = 999765} events_count = <optimized out> msecs = <optimized out> ret = 1 i = 0 call = <optimized out> #34 0x00007f4372c764b8 in io_loop_run (ioloop=0x12c06a0) at ioloop.c:398 No locals. #35 0x00007f4372c62113 in master_service_run (service=0x12c0550, callback=callback@entry=0x418f40 <client_connected>) at master-service.c:544 No locals. #36 0x00000000004088e3 in main (argc=2, argv=0x12c0390) at main.c:389 set_roots = {0x41c2a0 <imap_setting_parser_info>, 0x0} login_set = {auth_socket_path = 0x12b8090 "/run/dovecot/auth-master", postlogin_socket_path = 0x12b80c0 "/run/dovecot/imap-postlogin", postlogin_timeout_secs = 60, callback = 0x4193d0 <login_client_connected>, failure_callback = 0x4190e0 <login_client_failed>} service_flags = <optimized out> storage_service_flags = <optimized out> username = 0x0 c = <optimized out>