Mail having IO errors, tied to LDAP. At wits end.

Our mail server is crashing about once a day, give or take. The console log will typically look like this prior to, then during the crash. Server is a Quad Xeon at 10.4.10 [code]Sep 25 16:58:53 zappa ntpd[328]: sendto(17.254.0.31): Bad file descriptor Sep 25 17:17:57 zappa DirectoryService[82]: Search connection failure: During an attempt to bind to [127.0.0.1] LDAP server. Sep 25 17:17:57 zappa DirectoryService[82]: Search connection failure: Disabled future attempts to bind to [127.0.0.1] LDAP server for next 0 seconds. Sep 25 17:19:19 zappa DirectoryService[82]: GSSAPI Error: Miscellaneous failure (Server not found in Kerberos database) Sep 25 17:19:19 zappa DirectoryService[82]: GSSAPI Error: Miscellaneous failure (Server not found in Kerberos database) Sep 25 17:19:19 zappa DirectoryService[82]: GSSAPI Error: Miscellaneous failure (Server not found in Kerberos database) Sep 25 17:19:19 zappa DirectoryService[82]: GSSAPI Error: Miscellaneous failure (Server not found in Kerberos database) Sep 25 17:19:19 zappa DirectoryService[82]: GSSAPI Error: Miscellaneous failure (Server not found in Kerberos database) Sep 25 17:19:19 zappa DirectoryService[82]: GSSAPI Error: Miscellaneous failure (Server not found in Kerberos database) Sep 25 17:19:19 zappa DirectoryService[82]: GSSAPI Error: Miscellaneous failure (Server not found in Kerberos database) Sep 25 17:19:20 zappa DirectoryService[82]: GSSAPI Error: Miscellaneous failure (Server not found in Kerberos database) Sep 25 17:19:20 zappa DirectoryService[82]: GSSAPI Error: Miscellaneous failure (Server not found in Kerberos database) Sep 25 17:19:20 zappa DirectoryService[82]: GSSAPI Error: Miscellaneous failure (Server not found in Kerberos database) Sep 25 17:19:20 zappa DirectoryService[82]: GSSAPI Error: Miscellaneous failure (Server not found in Kerberos database) Sep 25 17:19:20 zappa DirectoryService[82]: GSSAPI Error: Miscellaneous failure (Server not found in Kerberos database) Sep 25 17:19:20 zappa DirectoryService[82]: GSSAPI Error: Miscellaneous failure (Server not found in Kerberos database) Sep 25 17:19:20 zappa DirectoryService[82]: GSSAPI Error: Miscellaneous failure (Server not found in Kerberos database) Sep 25 17:19:20 zappa DirectoryService[82]: GSSAPI Error: Miscellaneous failure (Server not found in Kerberos database) Sep 25 17:19:20 zappa DirectoryService[82]: GSSAPI Error: Miscellaneous failure (Server not found in Kerberos database) Sep 25 17:19:20 zappa DirectoryService[82]: GSSAPI Error: Miscellaneous failure (Server not found in Kerberos database) Sep 25 17:19:20 zappa DirectoryService[82]: GSSAPI Error: Miscellaneous failure (Server not found in Kerberos database) 2007-09-25 17:20:59.386 Server Admin[11887] Server got an empty response (servermgr_info may have crashed) 2007-09-25 17:20:59.386 Server Admin[11887] Disabling multithreaded transactions for zappa.local 2007-09-25 17:20:59.386 Server Admin[11887] Server got an empty response (servermgr_info relay may have crashed) Sep 25 17:21:20 zappa DirectoryService[82]: Search connection failure: During an attempt to bind to [127.0.0.1] LDAP server. Sep 25 17:21:20 zappa DirectoryService[82]: Search connection failure: Disabled future attempts to bind to [127.0.0.1] LDAP server for next 0 seconds. Sep 25 17:21:50 zappa imaps[29671]: AOD: authentication error: cannot find user: john (0) DSOpenNode(): dsOpenDirNode("/LDAPv3/127.0.0.1") == -14002 Sep 25 17:22:35 zappa /System/Library/CoreServices/mcxd.app/Contents/MacOS/mcxd: DSOpenNode(): dsOpenDirNode("/LDAPv3/127.0.0.1") == -14002 Sep 25 17:22:52 zappa DirectoryService[82]: Search connection failure: During an attempt to bind to [10.1.1.6] LDAP server. Sep 25 17:22:52 zappa DirectoryService[82]: Search connection failure: Disabled future attempts to bind to [10.1.1.6] LDAP server for next 0 seconds. Sep 25 17:24:27 zappa imaps[21391]: IOERROR: stat /var/imap/mailboxes.db: Resource temporarily unavailable Sep 25 17:24:27 zappa imaps[21391]: DBERROR: error fetching user.bob.Drafts: cyrusdb error[/code] We're not using Kerberos at the moment for anything in an effort to try and narrow down where the problem may lie. (blocked at the server firewall) After it starts erroring out, stopping mail, rebuilding the clients and mail DB and firing it back up has it back on its feet and running in two minutes. However, these crashes are driving me insane. I tried rebuilding the slapd index last night and that didn't seem to make any difference. (per the [url=https://www.afp548.com/forum/viewtopic.php?forum=18&showtopic=16535]thread[/url] here) The GSSAPI errors began after we cut off the Kerberos port, but we saw piles of them today and they didn't adversely affect service. The crashes that we'd experienced in the past happened without any GSSAPI errors in the logs. The last slapd.log entries before it dies are as follows [code]Sep 25 17:22:50 zappa slapd[66]: