Messages in this thread |  | | Date | Thu, 29 Jul 2004 11:56:48 +0200 | | From | Jan Oravec <> | | Subject | LSI 53c1030 (Fusion MPT) performance with O_SYNC |
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Hi,
I have got a new dual-Opteron server based on Tyan S2880 motherboard with LSI53C1030 U320 controller onboard - there are 15kRPM Fujitsu disks.
I've noticed poor performance with MySQL/InnoDB when compared to another S2880-based box with IDE disks.
I've tracked it to this:
Let's have this code (notice the O_SYNC) and enough large test file.
#include <sys/types.h> #include <sys/stat.h> #include <fcntl.h> #include <unistd.h>
int main(int argc, void **argv) { char buffer[64]; int fd, i;
fd=open(argv[1], O_WRONLY|O_SYNC); lseek(fd, 0, SEEK_SET); for(i=0; i<10000; i++) write(fd, buffer, 64); return 0; }
The results are:
LSI53C1030: $ time ./a.out testfile
real 0m4.218s user 0m0.002s sys 0m0.219s
IDE: $ time ./a.out testfile
real 0m1.767s user 0m0.002s sys 0m0.356s
Changing size of written amount of data to 4096 the time ratio between LSI53C1030 and IDE is around 1:1.
Both boxes are running vanilla 2.6.7 kernel.
Any help appreciated,
Jan
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