From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from pigeon.gentoo.org ([208.92.234.80] helo=lists.gentoo.org) by finch.gentoo.org with esmtp (Exim 4.60) (envelope-from ) id 1PzO7Q-00078X-Ty for garchives@archives.gentoo.org; Tue, 15 Mar 2011 06:52:37 +0000 Received: from pigeon.gentoo.org (localhost [127.0.0.1]) by pigeon.gentoo.org (Postfix) with SMTP id 31DF11C002; Tue, 15 Mar 2011 06:50:52 +0000 (UTC) Received: from mail1.deploylinux.net (mail1.deploylinux.net [209.216.192.150]) by pigeon.gentoo.org (Postfix) with ESMTP id DF7371C002 for ; Tue, 15 Mar 2011 06:50:51 +0000 (UTC) Received: from localhost (localhost.localdomain [127.0.0.1]) by mail1.deploylinux.net (Postfix) with ESMTP id 69DE026CFFB for ; Mon, 14 Mar 2011 23:50:51 -0700 (PDT) X-Virus-Scanned: amavisd-new at deploylinux.net Received: from mail1.deploylinux.net ([127.0.0.1]) by localhost (mail1.deploylinux.net [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id pTbOKVePRELp for ; Mon, 14 Mar 2011 23:50:50 -0700 (PDT) Received: from hyperion.deploylinux.net (hyperion.deploylinux.net [66.93.35.200]) by mail1.deploylinux.net (Postfix) with ESMTPSA id 9D7FA26CFEC for ; Mon, 14 Mar 2011 23:50:50 -0700 (PDT) From: Matthew Marlowe Organization: DeployLinux Consulting, Inc To: gentoo-user@lists.gentoo.org Subject: Re: [gentoo-user] terrible performance with btrfs on LVM2 using a WD 2TB green drive Date: Mon, 14 Mar 2011 23:50:49 -0700 User-Agent: KMail/1.13.5 (Linux/2.6.36-gentoo-r7a; KDE/4.4.5; x86_64; ; ) References: <1300167466.30677.32.camel@troll> In-Reply-To: <1300167466.30677.32.camel@troll> Precedence: bulk List-Post: List-Help: List-Unsubscribe: List-Subscribe: List-Id: Gentoo Linux mail X-BeenThere: gentoo-user@lists.gentoo.org Reply-to: gentoo-user@lists.gentoo.org MIME-Version: 1.0 Content-Type: Text/Plain; charset="utf-8" Content-Transfer-Encoding: 7bit Message-Id: <201103142350.49670.matt@deploylinux.net> X-Archives-Salt: X-Archives-Hash: 125993ca96506c8e3faacb369ecfcfae > My problem is that LVM2 is not supported in parted which is the > recommended tool to deal with this. > > I suspect I only need to map the individual PE to a particular start > sector on each drive, not btrfs, but then there is stripe/block sizes to > consider as well ... WD also are recommending 1mb sector boundaries for > best performance - I can see a reinstall coming up :) > I have on my workstation: 2 WD 2TB Black Drives 5 WD 2TB RE4 Drives Some notes: - The black drives have horrible reliability, poor sector remapping, and have certain standard drive features to make them unusable in raid. I would not buy them again. I'm not sure how similar the green drives are. - Many of the recent WD drives have a tendency to power down/up frequently which can reduce drive lifetime (research it and ensure it is set appropriately for your needs). - Due to reliability concerns, you'll may need to run smartd to give adequate pre-failure warnings Anyhow, in my config I have: 1 RE4 Drive as Server Boot Disk 4 RE4 Drives in SW RAID10 (extremely good performance and reliability) 2 Black Drives in LVM RAID0 for disk-to-disk backups (thats about all I trust them with). When I setup the LVM RAID0, I used the following commands to get good performance: fdisk (remove all partitions, you don't need them for lvm) pvcreate --dataalignmentoffset 7s /dev/sdd pvcreate --dataalignmentoffset 7s /dev/sdf vgcreate -s 64M -M 2 vgArchive /dev/sdd /dev/sdf lvcreate -i 2 -l 100%FREE -I 256 -n lvArchive -r auto vgArchive mkfs.ext4 -c -b 4096 -E stride=64,stripe_width=128 -j -i 1048576 -L /archive /dev/vgArchive/lvArchive I may have the ext4 stride/stripe settings wrong above, I didn't have my normal notes when I selected them - but the rest of the config I scrounged from other blogs and seemed to make sense (the --dataalignmentoffset 7s) seems to be the key. My RAID10 drives are configured slightly different w/ 1 partition that starts on sector 2048 if I remember and extends to the end of the drive. The 4 Disk SW RAID10 array gives me 255MB/s reads, 135MB/s block writes, and 98MB/s rewrites (old test, may need to rerun for latest changes/etc). LVM 2 Disk RAID0 gives 303MB/s reads, 190MB/s block writes, and 102MB/s rewrites (test ran last week). Regards, Matt -- Matthew Marlowe / 858-400-7430 / DeployLinux Consulting, Inc Professional Linux Hosting and Systems Administration Services www.deploylinux.net * matt@deploylinux.net 'MattM' @ irc.freenode.net