Hi, Cluster running Lustre 1.6.6 Opening and closing files takes longer on RHEL5 than on RHEL4. This is only happens with files located on Lustre file system. To reproduce this problem I used small c code (located on the bottom of my email). Is this a known problem? RH4 ===real 6m24.951s user 0m1.113s sys 0m43.983s real 3m21.464s user 0m1.011s sys 0m41.795s real 3m15.305s user 0m0.685s sys 0m34.321s real 3m52.444s user 0m1.073s sys 0m41.246s RH5 ===real 6m56.701s user 0m0.602s sys 0m52.233s real 5m28.310s user 0m0.613s sys 0m48.284s real 5m19.244s user 0m0.555s sys 0m44.684s real 6m9.290s user 0m0.613s openclose.c =====#include <stdio.h> #include <stdlib.h> int openClose() { FILE *fp; if((fp = fopen("test.dat", "w+")) == NULL) { printf("open error\n"); exit(1); } if( fclose( fp )) { printf("close error\n"); } return 0; } int main(void) { int i; for(i = 0; i < 300000; i++) { openClose(); } } -- -- Wojciech Turek Assistant System Manager High Performance Computing Service University of Cambridge Email: wjt27 at cam.ac.uk -------------- next part -------------- An HTML attachment was scrubbed... URL: http://lists.lustre.org/pipermail/lustre-discuss/attachments/20091111/73f39c4d/attachment.html