Hello Timo, I can reproduce this issue even with mmap_disable and mmap_no_write set to yes, please see the following back trace:

$ gdb /usr/local/libexec/dovecot/imap /tmp/imap.core GNU gdb 6.3 Copyright 2004 Free Software Foundation, Inc. GDB is free software, covered by the GNU General Public License, and you are welcome to change it and/or distribute copies of it under certain conditions. Type "show copying" to see the conditions. There is absolutely no warranty for GDB. Type "show warranty" for details. This GDB was configured as "i386-unknown-openbsd3.6"... Core was generated by `imap'. Program terminated with signal 11, Segmentation fault. Reading symbols from /usr/lib/libc.so.34.2...done. Loaded symbols for /usr/lib/libc.so.34.2 Reading symbols from /usr/libexec/ld.so...done. Loaded symbols for /usr/libexec/ld.so #0 0x1c03d7f2 in mail_transaction_log_view_set (view=0x3c020500, min_file_seq=8, min_file_offset=7148, max_file_seq=8, max_file_offset=7148, type_mask=8) at mail-transaction-log-view.c:102 102 if (min_file_seq == view->log->tail->hdr.prev_file_seq && (gdb) #0 0x1c03d7f2 in mail_transaction_log_view_set (view=0x3c020500, min_file_seq=8, min_file_offset=7148, max_file_seq=8, max_file_offset=7148, type_mask=8) at mail-transaction-log-view.c:102 file = (struct mail_transaction_log_file *) 0x2b1dbec8 first = (struct mail_transaction_log_file *) 0xb21b372 seq = 0 end_offset = 4324021345303134216 ret = 3932679 #1 0x1c03a17a in view_sync_get_expunges (view=0x3c01f700, expunges_r=0xcfbf97d0) at mail-index-view-sync.c:105 hdr = (const struct mail_transaction_header *) 0xe4e1c00 src = (struct mail_transaction_expunge *) 0xff src_end = (struct mail_transaction_expunge *) 0x3c011020 dest = (struct mail_transaction_expunge *) 0x0 data = (const void *) 0x23ee00 count = 1117130127 ret = 8 #2 0x1c03a366 in mail_index_view_sync_begin (view=0x3c01f700, sync_mask=255, ctx_r=0x8) at mail-index-view-sync.c:176 hdr = (const struct mail_index_header *) 0x3c01f804 ctx = (struct mail_index_view_sync_ctx *) 0x1c039b4d map = (struct mail_index_map *) 0xff mask = 8 want_mask = 0 expunges = {buffer = 0x0, element_size = 0} #3 0x1c02d6cd in index_mailbox_sync_init (box=0x3c01e840, flags=0, failed=0) at index-sync.c:150 ctx = (struct index_mailbox_sync_context *) 0x3c011020 sync_mask = 1006764673 #4 0x1c019b25 in maildir_storage_sync_init (box=0x3c01e840, flags=MAILBOX_SYNC_FLAG_FAST) at maildir-sync.c:991 ctx = (struct maildir_sync_context *) 0x3c0139b0 ret = 0 #5 0x1c040fc4 in mailbox_sync_init (box=0x8, flags=MAILBOX_SYNC_FLAG_FAST) at mail-storage.c:333 No locals. #6 0x1c015150 in imap_sync_init (client=0x3c020000, box=0x3c01e840, flags=MAILBOX_SYNC_FLAG_FAST) at imap-sync.c:43 ctx = (struct imap_sync_context *) 0x3c01d1c0 #7 0x1c01554f in cmd_sync (cmd=0x3c020040, flags=MAILBOX_SYNC_FLAG_FAST, tagline=0x3c00056f "OK Search completed.") at imap-sync.c:210 ctx = (struct cmd_sync_context *) 0x3c0230a0 #8 0x1c00eb66 in cmd_search (cmd=0x3c020040) at cmd-search.c:102 client = (struct client *) 0x3c020000 sargs = (struct mail_search_arg *) 0x8 args = (struct imap_arg *) 0x3c021048 args_count = 8 error = 0x0 charset = 0x0 #9 0x1c00fa7d in cmd_uid (cmd=0x3c020040) at cmd-uid.c:19 cmd_name = 0x3c0210f8 "SEARCH" #10 0x1c01023b in client_handle_input (cmd=0x3c020040) at client.c:334 client = (struct client *) 0x3c020000 #11 0x1c010369 in _client_input (context=0x3c020000) at client.c:383 client = (struct client *) 0x3c020000 cmd = (struct client_command_context *) 0x3c020040 #12 0x1c050a68 in io_loop_handler_run (ioloop=0x3c01d000) at ioloop-poll.c:184 data = (struct ioloop_handler_data *) 0x3c0110a0 pollfd = (struct pollfd *) 0x3c01e000 tv = {tv_sec = 7, tv_usec = 9219} io = (struct io *) 0x3c0111c0 t_id = 2 msecs = 8 ret = 0 call = 1 #13 0x1c050505 in io_loop_run (ioloop=0x3c01d000) at ioloop.c:218 No locals. #14 0x1c016d37 in main (argc=3, argv=0xcfbf9a3c, envp=0xcfbf9a4c) at main.c:228 No locals. (gdb)

Any suggestions how to fix these ongoing problems?

Thanks, Tero

-- Tero Ripattila