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? I will be grateful for any suggestions.
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: [email protected]
Tel: (+)44 1223 763517
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