Comment 274 for bug 620074

PC010233L vmware # dd if=/dev/zero of=/tmp/bigfile bs=1M count=10000 conv=fdatasync &
[1] 10528
PC010233L vmware # sleep 10
PC010233L vmware # time dd if=/dev/zero of=/tmp/smallfile bs=4k count=1 conv=fdatasync
1+0 records in
1+0 records out
4096 bytes (4.1 kB) copied, 0.00333981 s, 1.2 MB/s

real 0m0.054s
user 0m0.000s
sys 0m0.000s
PC010233L vmware #
PC010233L vmware # time dd if=/dev/zero of=/tmp/smallfile bs=4k count=1 conv=fdatasync
1+0 records in
1+0 records out
4096 bytes (4.1 kB) copied, 0.604249 s, 6.8 kB/s

real 0m3.219s
user 0m0.000s
sys 0m0.000s

The second time I ran the second DD was about 2 minutes later. My / (or /tmp)
is located on a WD 10K RPM SATA II Drive.

And after fixing the dirty ratios....

PC010233L vmware # dd if=/dev/zero of=/tmp/bigfile bs=1M count=10000 conv=fdatasync &
[1] 10548
PC010233L vmware # sleep 10
PC010233L vmware # time dd if=/dev/zero of=/tmp/smallfile bs=4k count=1 conv=fdatasync
1+0 records in
1+0 records out
4096 bytes (4.1 kB) copied, 1.41179 s, 2.9 kB/s

real 0m2.044s
user 0m0.000s
sys 0m0.002s
PC010233L vmware # time dd if=/dev/zero of=/tmp/smallfile bs=4k count=1 conv=fdatasync
1+0 records in
1+0 records out
4096 bytes (4.1 kB) copied, 0.000649804 s, 6.3 MB/s

real 0m6.366s
user 0m0.000s
sys 0m0.002s
PC010233L vmware #

Again, second one was about 2 minutes afterwards.