Skip site navigation (1)Skip section navigation (2)
Date:      Sun, 22 Jul 2012 02:19:32 -0400
From:      "Dieter BSD" <dieterbsd@engineer.com>
To:        hackers@freebsd.org,current@freebsd.org
Subject:   Re: Awful FreeBSD 9 block IO performance in KVM
Message-ID:  <20120722061933.298410@gmx.com>

next in thread | raw e-mail | index | archive | help
>>> da0: 3.300MB/s transfers
>>> da0: Command Queueing enabled
>
> root@freebsd:/root # dd if=/dev/zero of=/dev/da1 bs=16384 count=262144
>
> 4294967296 bytes transferred in 615.840721 secs (6974153 bytes/sec)

1) Does a larger block size (bs=1m) help?

2) That's roughly the speed I'd expect without queueing. Is it really
making effective use of queueing, or is something limiting queueing to
one transfer at a time?



Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?20120722061933.298410>