Greetings, A Squid server (RHEL-5.2 64-bit) is serving around 1000 users with NTLM (winbindd), Basic, wbinfo, and URL rewriter (Websense). Squid has randomly crashed with the following messages: FATAL: Received Segment Violation...dying. 2010/01/20 15:53:29| storeDirWriteCleanLogs: Starting... 2010/01/20 15:53:29| WARNING: Closing open FD 183 2010/01/20 15:53:29| commSetEvents: epoll_ctl(EPOLL_CTL_DEL): failed on fd=183: (1) Operation not permitted 2010/01/20 15:53:29| 65536 entries written so far. 2010/01/20 15:53:29| 131072 entries written so far. ... ... 2010/01/20 15:53:35| Finished. Wrote 10511684 entries. 2010/01/20 15:53:35| Took 6.2 seconds (1702503.8 entries/sec). CPU Usage: 3406.086 seconds = 2431.073 user + 975.013 sys Maximum Resident Size: 0 KB Page faults with physical i/o: 3 Memory usage for squid via mallinfo(): total space in arena: -1092812 KB Ordinary blocks: -1096748 KB 3986 blks Small blocks: 0 KB 24 blks Holding blocks: 24108 KB 8 blks Free Small blocks: 1 KB Free Ordinary blocks: 3935 KB Total in use: -1072640 KB 100% Total free: 3936 KB 0% 2010/01/20 15:54:48| Starting Squid Cache version 2.7.STABLE7 for x86_64-unknown-linux-gnu... Ran gdb over the core dump file and got this result: # gdb /usr/local/squid/sbin/squid core.30068 GNU gdb Red Hat Linux (6.5-37.el5rh) Copyright (C) 2006 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 "x86_64-redhat-linux-gnu"...Using host libthread_db library "/lib64/libthread_db.so.1". Reading symbols from /lib64/libcrypt.so.1...done. Loaded symbols for /lib64/libcrypt.so.1 Reading symbols from /lib64/libpthread.so.0...done. Loaded symbols for /lib64/libpthread.so.0 Reading symbols from /lib64/libm.so.6...done. Loaded symbols for /lib64/libm.so.6 Reading symbols from /lib64/libnsl.so.1...done. Loaded symbols for /lib64/libnsl.so.1 Reading symbols from /lib64/libc.so.6...done. Loaded symbols for /lib64/libc.so.6 Reading symbols from /lib64/ld-linux-x86-64.so.2...done. Loaded symbols for /lib64/ld-linux-x86-64.so.2 Reading symbols from /lib64/libnss_files.so.2...done. Loaded symbols for /lib64/libnss_files.so.2 Reading symbols from /lib64/libnss_dns.so.2...done. Loaded symbols for /lib64/libnss_dns.so.2 Reading symbols from /lib64/libresolv.so.2...done. Loaded symbols for /lib64/libresolv.so.2 Core was generated by `(squid)'. Program terminated with signal 6, Aborted. #0 0x000000376b630215 in raise () from /lib64/libc.so.6 (gdb) bt #0 0x000000376b630215 in raise () from /lib64/libc.so.6 #1 0x000000376b631cc0 in abort () from /lib64/libc.so.6 #2 0x0000000000474515 in death (sig=<value optimized out>) at tools.c:327 #3 <signal handler called> #4 0x000000000044271a in httpHeaderGetEntry (hdr=0x141868f8, pos=0x7fff2c609774) at HttpHeader.c:595 #5 0x00000000004427fe in httpHeaderFindEntry (hdr=0x141868f8, id=HDR_CONTENT_TYPE) at HttpHeader.c:619 #6 0x0000000000443037 in httpHeaderGetStr (hdr=0x141868f8, id=HDR_CONTENT_TYPE) at HttpHeader.c:1086 #7 0x00000000004075b9 in aclMatchAclList (list=0x2aaac246fa40, checklist=0x2aaad3524738) at acl.c:2010 #8 0x0000000000407d82 in aclCheck (checklist=0x2aaad3524738) at acl.c:2178 #9 0x000000000042daae in externalAclHandleReply (data=0x2aaab26015d0, reply=0x2aaac6951e38 "") at external_acl.c:985 #10 0x000000000043cd65 in helperHandleRead (fd=<value optimized out>, data=<value optimized out>) at helper.c:769 #11 0x0000000000427511 in comm_select (msec=<value optimized out>) at comm_generic.c:264 #12 0x000000000044f7a6 in main (argc=<value optimized out>, argv=0x7fff2c609a58) at main.c:863 The configure options read ./configure --prefix=/usr/local/squid --enable-async-io --enable-snmp --enab le-epoll --enable-storeio=aufs null --enable-removal-policies=heap lru --enable- large-cache-files --with-large-files --disable-poll --disable-select --disable-c arp --disable-wccp --disable-ident-lookups --with-maxfd=32768 --enable-ntlm-auth -helpers=SMB --enable-external-acl-helpers=wbinfo_group ldap_group --enable-auth =basic ntlm --enable-basic-auth-helpers=LDAP --enable-err-languages=English Snippet of squid.conf emulate_httpd_log on buffered_logs on debug_options ALL,1 logfile_daemon /usr/local/squid/libexec/logfile-daemon access_log daemon:/var/log/squid/access.log shutdown_lifetime 10 seconds cache_dir aufs /var/spool/squid/cache01 62500 32 256 cache_dir aufs /var/spool/squid/cache02 62500 32 256 cache_dir aufs /var/spool/squid/cache03 62500 32 256 cache_dir aufs /var/spool/squid/cache04 62500 32 256 cache_replacement_policy heap GDSF memory_replacement_policy heap GDSF cache_log /var/log/squid/cache.log cache_store_log none pid_filename /var/run/squid.pid coredump_dir /var/spool/squid/crash log_icp_queries off client_db on half_closed_clients off cache_mem 512 MB maximum_object_size 768000 KB maximum_object_size_in_memory 96 KB memory_pools off forwarded_for off snmp_port 1601 snmp_incoming_address 0.0.0.0 snmp_outgoing_address 255.255.255.255 auth_param ntlm program /usr/bin/ntlm_auth --helper-protocol=squid-2.5-ntlmssp auth_param ntlm children 30 auth_param ntlm keep_alive on auth_param basic program /usr/bin/ntlm_auth --helper-protocol=squid-2.5-basic auth_param basic children 5 auth_param basic realm User Authentication external_acl_type ads-group children=20 %LOGIN /usr/local/squid/libexec/wbinfo_group.pl url_rewrite_children 50 redirector_bypass off url_rewrite_program /opt/Websense/bin/WsRedtor Does anyone have any idea how to fix this problem? Many Thanks myOcella