Dear All, I run a 6 parallel processes with boost MPI on a system with OpenMPI. When the run-time of the program is short, it works well. But, if the run-time is long, I got errors: [n124:45521] *** Process received signal ***[n124:45521] Signal: Segmentation fault (11)[n124:45521] Signal code: Address not mapped (1)[n124:45521] Failing at address: 0x44[n124:45521] [ 0] /lib64/libpthread.so.0 [0x3c50e0e4c0][n124:45521] [ 1] /lib64/libc.so.6(strlen+0x10) [0x3c50278d60][n124:45521] [ 2] /lib64/libc.so.6(_IO_vfprintf+0x4479) [0x3c50246b19][n124:45521] [ 3] /lib64/libc.so.6(_IO_printf+0x9a) [0x3c5024d3aa][n124:45521] [ 4] /home/path/exec [0x40ec9a][n124:45521] [ 5] /lib64/libc.so.6(__libc_start_main+0xf4) [0x3c5021d974][n124:45521] [ 6] /home/path/exec [0x401139][n124:45521] *** End of error message *** It seems that there may be some problems about memory management. But, I cannot find the reason. My program needs to write results to some files. If I open the files too many without closing them, I may get the above errors. But, I have removed the writing files from my program. The problem appears again when the program runs longer time. Any help is appreciated. Jack July 25 2010 _________________________________________________________________ The New Busy is not the too busy. Combine all your e-mail accounts with Hotmail. http://www.windowslive.com/campaign/thenewbusy?tile=multiaccount&ocid=PID28326::T:WLMTAGL:ON:WL:en-US:WM_HMP:042010_4