gmirror on a very slow but new HP architecture

[Pawel Jakub Dawidek]

On Mon, Apr 07, 2008 at 08:48:05PM +0200, Ferruccio Zamuner wrote:
> free# swapoff /dev/mirror/gm0b
> free# dd if=/dev/zero of=/dev/mirror/gm0b bs=8192 count=10000
> 10000+0 records in
> 10000+0 records out
> 81920000 bytes transferred in 2.443927 secs (33519822 bytes/sec)
> free# dd if=/dev/mirror/gm0b of=/dev/null bs=8192 count=20000
> 20000+0 records in
> 20000+0 records out
> 163840000 bytes transferred in 7.773088 secs (21077852 bytes/sec)
> free# dd if=/dev/mirror/gm0b of=/dev/null bs=8192 count=20000
> 20000+0 records in
> 20000+0 records out
> 163840000 bytes transferred in 7.444171 secs (22009167 bytes/sec)
> free# dd if=/dev/zero of=/dev/mirror/gm0b bs=8192 count=20000
> 20000+0 records in
> 20000+0 records out
> 163840000 bytes transferred in 5.668771 secs (28902208 bytes/sec)
> free# dd if=/dev/mirror/gm0b of=/dev/null bs=8192 count=20000
> 20000+0 records in
> 20000+0 records out
> 163840000 bytes transferred in 8.050144 secs (20352430 bytes/sec)

Your test is too short and you are using too small block size. Try
something like this:

	# dd if=/dev/zero of=/dev/mirror/gm0b bs=128k count=10000
	# dd if=/dev/mirror/gm0b of=/dev/null bs=128k count=10000

Also, please provide the output of:

	# bsdlabel /dev/mirror/gm0

so we know 'b' partition is not placed at the end of the disk.

-- 
Pawel Jakub Dawidek                       http://www.wheel.pl
pjd at FreeBSD.org                           http://www.FreeBSD.org
FreeBSD committer                         Am I Evil? Yes, I Am!
-------------- next part --------------
A non-text attachment was scrubbed...
Name: not available
Type: application/pgp-signature
Size: 187 bytes
Desc: not available
Url : http://lists.freebsd.org/pipermail/freebsd-geom/attachments/20080412/6dfc7ae6/attachment.pgp