From owner-freebsd-stable@FreeBSD.ORG Sun Aug 8 17:23:10 2010 Return-Path: Delivered-To: freebsd-stable@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 43EA5106566C for ; Sun, 8 Aug 2010 17:23:10 +0000 (UTC) (envelope-from alexvpetrov@gmail.com) Received: from mail-ew0-f54.google.com (mail-ew0-f54.google.com [209.85.215.54]) by mx1.freebsd.org (Postfix) with ESMTP id C67958FC13 for ; Sun, 8 Aug 2010 17:23:09 +0000 (UTC) Received: by ewy26 with SMTP id 26so3765474ewy.13 for ; Sun, 08 Aug 2010 10:23:08 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma; h=domainkey-signature:received:received:from:to:subject:date :user-agent:references:in-reply-to:cc:mime-version:content-type :content-transfer-encoding:message-id; bh=R5E+TBbfoRd+9aoXxtiJmfkpLbsQYLZR/cMQyKzRuVU=; b=FEkQUpUdyUtUGzpWt/Dror7Wb01xHt6Vp90o7DxModEk0cA1WtLVI9phWkL5lZl8BB 5vD8W4qQW+LO1RP2EJhlGJ6Jyq2Rww+bMvwmtxHgS47o06gQYsABQ0UozxqafhcXqJkv ZQpvuReIBMmS1sAV9gBQwr/qG2/IACvgYTZi0= DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=from:to:subject:date:user-agent:references:in-reply-to:cc :mime-version:content-type:content-transfer-encoding:message-id; b=EDNmSiaaBRkU29bTXLzikQz6j2d7tN3HoShIjc47WR4id5cKLtX530VFoSNo4Rg5m0 MpavkvjcD7RYkImN14oCArsTTLHLD6IVgNVrT/bGI/oBw/gVFHxPvCREQAaL5ykwy+xJ 5FvalWYOMKywiBu89GR6eFx4v0GlyAESvIwkk= Received: by 10.213.109.14 with SMTP id h14mr1864299ebp.25.1281288188776; Sun, 08 Aug 2010 10:23:08 -0700 (PDT) Received: from alex.super ([91.195.101.86]) by mx.google.com with ESMTPS id a48sm6310798eei.13.2010.08.08.10.23.06 (version=TLSv1/SSLv3 cipher=RC4-MD5); Sun, 08 Aug 2010 10:23:08 -0700 (PDT) From: "Alex V. Petrov" To: Jeremy Chadwick Date: Mon, 9 Aug 2010 01:23:04 +0800 User-Agent: KMail/1.13.5 (FreeBSD/8.1-STABLE; KDE/4.4.5; amd64; ; ) References: <201008042008.25679.alexvpetrov@gmail.com> <201008051409.57751.alexvpetrov@gmail.com> <20100805061959.GA92106@icarus.home.lan> In-Reply-To: <20100805061959.GA92106@icarus.home.lan> MIME-Version: 1.0 Content-Type: Text/Plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable Message-Id: <201008090123.04823.alexvpetrov@gmail.com> Cc: freebsd-stable@freebsd.org Subject: Re: zpool - low speed write X-BeenThere: freebsd-stable@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Production branch of FreeBSD source code List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sun, 08 Aug 2010 17:23:10 -0000 =D0=92 =D1=81=D0=BE=D0=BE=D0=B1=D1=89=D0=B5=D0=BD=D0=B8=D0=B8 =D0=BE=D1=82 = 5 =D0=B0=D0=B2=D0=B3=D1=83=D1=81=D1=82=D0=B0 2010 14:19:59 =D0=B2=D1=8B =D0= =BD=D0=B0=D0=BF=D0=B8=D1=81=D0=B0=D0=BB=D0=B8: >=20 > Can you please remove use of the zpool entirely (e.g. zpool destroy > tank) and do a write test to each disk itself? E.g.: >=20 > dd if=3D/dev/zero of=3D/dev/ad8 bs=3D64k count=3D1000000 > dd if=3D/dev/zero of=3D/dev/ad10 bs=3D64k count=3D1000000 > dd if=3D/dev/zero of=3D/dev/ad12 bs=3D64k count=3D1000000 >=20 > I don't recommend using large block sizes (e.g. bs=3D1M, bs=3D3M). dd if=3D/dev/zero of=3D/dev/ad8 bs=3D64k count=3D1000000 1000000+0 records in 1000000+0 records out 65536000000 bytes transferred in 604.849406 secs (108350937 bytes/sec) dd if=3D/dev/zero of=3D/dev/ad10 bs=3D64k count=3D1000000 1000000+0 records in =20 1000000+0 records out 65536000000 bytes transferred in 757.755459 secs (86487005 bytes/sec) dd if=3D/dev/zero of=3D/dev/ad12 bs=3D64k count=3D1000000 1000000+0 records in 1000000+0 records out 65536000000 bytes transferred in 604.857282 secs (108349526 bytes/sec) =20 > If all of the above dds show good/decent throughput, then there's > something strange going on with ZFS. If this is the case, I would > recommend filing a PR and posting to freebsd-fs about the problem, > pointing folks to this thread. >=20 > If all of the dds show bad throughput, then could you please do the > following: >=20 > - Provide vmstat -i output > - Install ports/sysutils/smartmontools and run smartctl -a /dev/ad8, > smartctl -a /dev/ad10, and smartctl -a /dev/ad12 >=20 > If only one of the dds shows bad throughput, then please: >=20 > - Install ports/sysutils/smartmontools and run smartctl -a /dev/XXX, > where XXX is the disk which has bad throughput > - Try making a ZFS pool with all 3 disks, but then do "zpool offline > tank XXX" and then re-attempt the following dd: > dd if=3D/dev/zero of=3D/tank/test.zero bs=3D64k count=3D1000000 > And see what throughput looks like. >=20 > Thanks. =2D---- Alex V. Petrov