Assert Failed: Possible memory block header corruption

INFORMIX server aborted because of "Possible memory block header corruption". In these 2 months, it's the 6th time the ONLINE server aborted due to the same reason. I don't know how to solve it. The local (Taiwan) Informix don't know, either. Any response to help me solve the problem is appreciated! My boss would kill me if I can't solve it in 3 weeks... HELP!!! The system information: Running Environment: ==================== INFORMIX-OnLine Dynamic Server 7.14.UD1X4 SunOS 5.5.1 sun4d SparcCenter 2000 16 CPUs 1G Memory :::::::: OnLine.Log :::::::::::: 14:38:43 Checkpoint Completed: duration was 1 seconds. 14:40:30 Logical Log 3068 Complete. 14:41:53 Pool = 0x15580010, Pool name = 5033, Blkhdr = 0x27fff0 14:41:53 Block magic is 12991, expecting 31201 14:41:53 Assert Failed: Possible memory block header corruption 14:41:53 Who:Session(5033, bmsshell@gsms05b, 27591, 0) Thread(5090, sqlexec, 0, 14) 14:41:53 Action: Please notify Informix Technical Support. 14:41:53 See Also: /tmp/af.13e201b1, shmem.13e201b1.0 14:43:09 mtshpool.c, line 2551, thread 5090, proc id 427, Condition Failed (CHECK_ALLOC_BLOCK), In (mt_shm_free) Thread(5090, sqlexec, 0, 14). 14:43:10 Panic: Attempting to bring system down :::::::: /tmp/af.13e201b1 :::::::::::::::::::::::::::::::::::::::::::::: 14:41:53 Pool = 0x15580010, Pool name = 5033, Blkhdr = 0x27fff0 14:41:53 Block magic is 12991, expecting 31201Block header - 64 0027ffb0: d202610c d2026004 80a26000 02800011 ..a...`. ..`..... 0027ffc0: 9405e13c d204e000 d202400a d202610c ...<.... ..@...a. 0027ffd0: 80a26000 02bffff2 9405e13c d204e000 ..`..... ...<.... 0027ffe0: d202400a d202610c d2026004 80a26000 ..@...a. ..`...`. Block header + 64 0027fff0: 32bfffe4 e004e000 10bfffe9 01000000 2....... ........ 00280000: 7fffdf00 a205e13c e004e000 e0040011 .......< ........ 00280010: 40020126 d0042004 a205e13c e004e000 @..&.. . ...<.... 00280020: e0040011 e0042100 80a42000 02800029 ......!. .. ....) 14:41:53 14:41:53 Assert Failed: Possible memory block header corruption 14:41:53 Who:Session(5033, bmsshell@gsms05b, 27591, 0) Thread(5090, sqlexec, 0, 14) 14:41:53 Action: Please notify Informix Technical Support. 14:41:53 See Also: /tmp/af.13e201b1, shmem.13e201b1.0 14:41:53 Stack for thread: 5090 sqlexec base: 0x16ee6010 len: 66048 pc: 0x00321a40 tos: 0x16ef5910 0x00321480 mt_affail (0x13e201b1, 0x153f3608, 0x0, 0x0, 0x0, 0x0) 0x0031c4d0 mem_asfail_alloc_block(0x15580010, 0x27fff0, 0x3c1c3c, 0x393cf4, 0x1, 0xf0715a80) 0x0031a6d8 mt_shm_free (0x15580010, 0x280000, 0xc00000, 0x14000000, 0x3a2e88, 0x0) 0x002e89b8 do_rhpfree (0x164dc018, 0x15580010, 0x164dc020, 0x0, 0x0, 0x14368170) 0x0015ef58 freedynm (0x0, 0x0, 0x1, 0x0, 0x16a730c0, 0x16ef600c) 0x0015af38 rollbacktx (0x1, 0x0, 0x0, 0x0, 0x0, 0x15580df9) 0x0015c99c excommand (0x1000, 0x0, 0x1701b0b8, 0x3cf18c, 0x0, 0xe175fc08) 0x00135094 sq_execute (0x0, 0x0, 0x0, 0x70, 0x380, 0x16ef61ac) 0x001467d8 sqmain (0x3d7bf0, 0x3cf18c, 0x7, 0x3d7c00, 0xa, 0xf04a1818) 0x00305d24 startup (0x0, 0x2, 0x1406c994, 0x14569a40, 0x1, 0x3d7cfc) 0x00301b90 mt_poll_yield (0x0, 0x0, 0x0, 0x0, 0x0, 0x0) 0x00000000 ***unknown*** 14:43:09 ------------------ End of assertion failure 0 ----------------- :::::::::::::::::: $INFORMIXDIR/etc/$ONCONFIG :::::::::::::::::::::: LOCKS 350000 BUFFERS 6000 NUMAIOVPS 16 PHYSBUFF 64 LOGBUFF 32LOGSMAX 400 CLEANERS 16 SHMBASE 0xa000000 SHMVIRTSIZE 120000 SHMADD 30000 SHMTOTAL 0 CKPTINTVL 900 LRUS 32 LRU_MAX_DIRTY 6 LRU_MIN_DIRTY 3LXTXHWM 50 LXTXEHWM 60 TXTIMEOUT 0x12c STACKSIZE 64 :::::::::::::: /etc/system ::::::::::::::::::::::::: *---------------- Informix online 7.1x ---------------------------------- set enable_sm_wa = 1 set shmsys:shminfo_shmmax=1310720000 set semsys:seminfo_semmni=4096 set semsys:seminfo_semmns=4096 set semsys:seminfo_semmnu=4096 set semsys:seminfo_semume=64 set semsys:seminfo_semmsl=100 set shmsys:shminfo_shmmin=100 *- set shmsys:shminfo_shmmni=100 set shmsys:shminfo_shmseg=100 P.S. INFORMIX-OnLine didn't dynamically add shared-mem before down. -- Fu-Xiong Lin