domU performance

[Kai Mosebach]

Hi,

just as a note, since it is not important in the current state, i guess (but maybe you might have some tweaking tips)

Testing the raw performance on my domU (r188436 compiled without WITNESS) seems to fall behind a Linux domU on the same machine:

BSD8 Reading:
# dd if=/dev/ad0s1 bs=1024k | cpipe -vt -b 65535 | cat >/dev/null
...
thru: 1200.000ms at   53.3MB/s (  57.3MB/s avg)    2.2GB
...
2401239040 bytes transferred in 40.000000 secs (60030976 bytes/sec)

BSD8 Writing :
# dd if=/dev/zero bs=1024k | cpipe -vt -b 65535 |dd of=/bigfile
...
thru: 4400.000ms at   14.5MB/s (  13.2MB/s avg)    2.8GB
...
3044998656 bytes transferred in 222.500000 secs (13685387 bytes/sec)


On the Linux side i get

Linux Reading (~15% faster):
# dd if=/dev/sda bs=1024k | cat | dd of=/dev/null 
4870635520 bytes (4.9 GB) copied, 73.7775 seconds, 66.0 MB/s

Linux Writing: (~90% faster)
# dd if=/dev/zero bs=1024k | cat | dd of=/root/test2
2473590784 bytes (2.5 GB) copied, 98.9709 seconds, 25.0 MB/s

cheers Kai