Test configuration:
Linux kernel 2.6.23.1 #1 SMP
2x Intel(R) Xeon(TM) CPU 2.40GHz with HT
iSCSI storage (1TB - 7 sata disks in RAID6, 2GB cache controler)
Yes, your "test" works fine:
file1:/mnt/hosting/test# time ./test
real 0m0.334s
user 0m0.000s
sys 0m0.000s
Is there any way to get it work for perl/php/other scripts/programs?
DS
On Fri, Feb 15, 2008 at 06:36:06PM -0600, Eric Sandeen wrote:
> DS wrote:
> > Hello,
> >
> > I need some help to tunning my storage.
>
> ...
> > TIME 43 sekund
>
>
> What kernel? when I test on my 2.6.23.9-85.fc8 and 2.6.22.5 boxes, I
> see 2 and 7 seconds for rewrite, respectively.
>
> but granted, on ext3 I get 0 seconds for every run.
>
> Also the difference appears to be O_TRUNC (which the perl script does);
> if I code it in c:
>
> #include <sys/types.h>
> #include <sys/stat.h>
> #include <fcntl.h>
>
> void main(void)
> {
> int i;
> int fd;
> char file[4];
>
> for (i = 0; i < 100; i++) {
> sprintf(file, "%d.txt", i);
> fd = open(file, O_CREAT|O_RDWR|O_TRUNC, 0644);
> write(fd, "aaaaaaaaaaaaaaaaaaa\n");
> close(fd);
> }
> }
>
> rewrite is a bit slower w/ O_TRUNC in place, plenty fast w/o it. Not
> sure about the xfs/ext3 difference... this is probably a side-effect of
> flushes xfs put into place on truncate (IIRC?)
>
> -Eric
>
>
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