20 Oca 2007 Cts 19:45 tarihinde şunları yazmıştınız: [...] > > vaio cartman # hdparm -tT /dev/hda > > > > /dev/hda: > > Timing cached reads: 1576 MB in 2.00 seconds = 788.18 MB/sec > > Timing buffered disk reads: 74 MB in 3.01 seconds = 24.55 MB/sec > > > > > > [~]> time dd if=/dev/zero of=/tmp/1GB bs=1M count=1024 > > 1024+0 records in > > 1024+0 records out > > 1073741824 bytes (1,1 GB) copied, 77,2809 s, 13,9 MB/s > > > > real 1m17.482s > > user 0m0.003s > > sys 0m2.350s > > That's not bad at all ! I suspect that if your system becomes unresponsive, > it's because real writes start when the cache is full. And if you fill > 512 MB of RAM with data that you then need to flush on disk at 14 MB/s, it > can take about 40 seconds during which it might be difficult to do > anything. > > Try lowering the cache flush starting point to about 10 MB if you want > (2% of 512 MB) : > > # echo 2 >/proc/sys/vm/dirty_ratio > # echo 2 >/proc/sys/vm/dirty_background_ratio
After that I get, [~]> time dd if=/dev/zero of=/tmp/1GB bs=1M count=1024 1024+0 records in 1024+0 records out 1073741824 bytes (1,1 GB) copied, 41,7005 s, 25,7 MB/s real 0m41.926s user 0m0.007s sys 0m2.500s not bad! thanks :) Regards, ismail - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/