From owner-freebsd-fs@FreeBSD.ORG  Sat Mar  8 09:20:53 2008
Return-Path: <owner-freebsd-fs@FreeBSD.ORG>
Delivered-To: freebsd-fs@freebsd.org
Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34])
	by hub.freebsd.org (Postfix) with ESMTP id C9C18106566C
	for <freebsd-fs@freebsd.org>; Sat,  8 Mar 2008 09:20:53 +0000 (UTC)
	(envelope-from cedilla@gmail.com)
Received: from wa-out-1112.google.com (wa-out-1112.google.com [209.85.146.178])
	by mx1.freebsd.org (Postfix) with ESMTP id 9F9CD8FC1E
	for <freebsd-fs@freebsd.org>; Sat,  8 Mar 2008 09:20:53 +0000 (UTC)
	(envelope-from cedilla@gmail.com)
Received: by wa-out-1112.google.com with SMTP id k17so1048757waf.3
	for <freebsd-fs@freebsd.org>; Sat, 08 Mar 2008 01:20:52 -0800 (PST)
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma;
	h=domainkey-signature:received:received:message-id:date:from:user-agent:mime-version:to:subject:content-type:content-transfer-encoding;
	bh=sFe8MgvPr+/3j0EGpjzLBoKLxmam6yDCO9YnHXBOovE=;
	b=XzW7GTwJiSeRw37Da94bbCmgprHw4upuxIzklqkuuYIxOyAgfZ/vn4HKHfgiHc+g29pU4kQNXdbMcmtTRrs6gw+AnE03lVMoWI/7xlqclbAdA9o+7EWAgZZAmA5f5/Paz2qVP8IK8bzAFbl22509XCGQnI4yK1xcm0z/qGBICTc=
DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma;
	h=message-id:date:from:user-agent:mime-version:to:subject:content-type:content-transfer-encoding;
	b=UUC3TUzUBDR9mnTIUNeR3eIv/vPGwn9khrksyuIMceVaisAt1tJ7U++OBIJ9Tp1cpMIjdD9mK+RIiTK1/mk7R6vW+y622rO2CPTbVDwRaoMHRWmugxrxws8ehejdhpfpS4cHat0ELHcyplq3birwWRBs4AcyibqebRpJdFbDhRo=
Received: by 10.115.111.1 with SMTP id o1mr239822wam.87.1204966443236;
	Sat, 08 Mar 2008 00:54:03 -0800 (PST)
Received: from ?192.168.1.100? ( [75.36.57.52])
	by mx.google.com with ESMTPS id v35sm2645822wah.19.2008.03.08.00.53.59
	(version=TLSv1/SSLv3 cipher=RC4-MD5);
	Sat, 08 Mar 2008 00:54:00 -0800 (PST)
Message-ID: <47D25426.8050505@gmail.com>
Date: Sat, 08 Mar 2008 00:53:58 -0800
From: Reed Wilson <cedilla@gmail.com>
User-Agent: Thunderbird 2.0.0.12 (Windows/20080213)
MIME-Version: 1.0
To: freebsd-fs@freebsd.org
Content-Type: text/plain; charset=UTF-8; format=flowed
Content-Transfer-Encoding: 7bit
Subject: ZFS zvol write speed incredibly slow
X-BeenThere: freebsd-fs@freebsd.org
X-Mailman-Version: 2.1.5
Precedence: list
List-Id: Filesystems <freebsd-fs.freebsd.org>
List-Unsubscribe: <http://lists.freebsd.org/mailman/listinfo/freebsd-fs>,
	<mailto:freebsd-fs-request@freebsd.org?subject=unsubscribe>
List-Archive: <http://lists.freebsd.org/pipermail/freebsd-fs>
List-Post: <mailto:freebsd-fs@freebsd.org>
List-Help: <mailto:freebsd-fs-request@freebsd.org?subject=help>
List-Subscribe: <http://lists.freebsd.org/mailman/listinfo/freebsd-fs>,
	<mailto:freebsd-fs-request@freebsd.org?subject=subscribe>
X-List-Received-Date: Sat, 08 Mar 2008 09:20:53 -0000

Hi guys!

I just got 7.0-RELEASE installed and running on my home server, and I've 
noticed incredibly slow write speeds to a ZFS zvol. Reading speeds seem 
normal. It may be related to the OpenSolaris bug #6428639:
http://bugs.opensolaris.org/view_bug.do?bug_id=6428639

 >> To another zpool:
# dd if=junk of=/tank2/junk bs=65536
1024+0 records in
1024+0 records out
67108864 bytes transferred in 0.331802 secs (202255676 bytes/sec)

 >> To a zvol in the same pool:
dd if=junk of=/dev/zvol/tank/tempvol bs=65536
1024+0 records in
1024+0 records out
67108864 bytes transferred in 11.575167 secs (5797658 bytes/sec)

Using smaller block sizes exacerbates the problem (444606 bytes/sec with 
4096-byte blocks!)

-- Reed