Server hung ...

Dear Informix experts, Would you please help us overcome our problem ? We have successfully installed and run informix server with three databases and small volume of data. This is not a production server so user activities are low. The problem is that almost every week, our SUN workstation hung with error message like that shown below. Only oninit and sagent proceses make the server this way. --------------------------------------- BAD TRAP : cpu=0 type=0x34 rp=0x30261768 addr=0x10407c07 mmu_fsr=0x0 oninit : alignment error : [sometimes, sagent make this happen] addr:0x10407e07 pid=174, pc=0x1002e4 sp=0x0 tstate = 0x302617f80 context = 0x1e02 g1-g7=3b00000, 4a ..... [similar like before] begin traceback sp=302617f8 called from 1000845 fp = ... [hex number] called from .... ... called from ... end traceback panic[cpu0]/thread=0x5051b4a0 : trap syncing file systems ... 2 2 2 2 2 2 ... [cut] 2211 static and sysmap kernel pages 34 dynamic kernel ---------------------------------------- Sometime, the informix server hungs (although it doesn't make the whole computer hung) with the following messages : 11:37:42 Assert Failed: Memory free block header corruption detected in mt_shm_malloc_segid 1 11:37:42 Who: Session(163, username@hostname, 26600, 0) Thread(189, sqlexec, 0, 1) 11:37:42 Results: Unable to repair pool 11:37:42 Action: Please notify Informix Technical Support. 11:37:42 See Also: /tmp/af.bd1b96, shmem.bd1b96.0 11:37:42 Stack for thread: 189 sqlexec ---------------------------------------- I believe that this is memory problem (and UNIX system configuration too) so I've tried to track memory usage. From the first time the server is brought on line, the amount of free memory keeps decreasing (from 24 MB down to 11, 10, 7, 6, 2, 1; I use 'top' command to see how much RAM is free) although no additional processes are invoked. In addition, the shared memory segments used (onstat -g seg) do not change. I also suspect that the system could not give additional shared memory segment as requested by client processes, but there is no such message in online.log file. ---------------------------------------- Here are some information about informix server and the platform where it runs : INFORMIX OWS Version 7.20.UC2 SUN SunOS 5.5.1 Generic sun4u sparc SUNW,Ultra-1 64 MB memory installed 4 GB HD ---------------------------------------- I have tried to consult online administration manuals but all suggest that I should contact Informix Technical Support. I think that's right but I hope I can find some answers before doing that. Could anyone give me a clue on what may cause the problem ? Any help would be much appreciated. Thank you. Pranadjaja Informix DBA