From owner-freebsd-fs@FreeBSD.ORG Fri Dec 25 14:39:19 2009 Return-Path: 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 509931065692 for ; Fri, 25 Dec 2009 14:39:19 +0000 (UTC) (envelope-from wonslung@gmail.com) Received: from mail-ew0-f226.google.com (mail-ew0-f226.google.com [209.85.219.226]) by mx1.freebsd.org (Postfix) with ESMTP id D49C98FC1E for ; Fri, 25 Dec 2009 14:39:18 +0000 (UTC) Received: by ewy26 with SMTP id 26so5532809ewy.3 for ; Fri, 25 Dec 2009 06:39:17 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma; h=domainkey-signature:mime-version:received:in-reply-to:references :date:message-id:subject:from:to:cc:content-type; bh=5jg4xURstJxLN+ow2TO2Q4/MxmODdxDmkQDuDnkUji4=; b=kJxb5tWaMejIkoZMUe9QDpeRmTJxnzdHFTV8BtT8C9yqdiT/rnRKjt1Fz8nnX2a5Sd vYgqG/1Kjd7ozLJmY10z/2XTiOeqtw88I/9SKrvdD/q4MSQcBkD+B7b8t9YYmrwkspaO CFfZeNkZwjQB/MRXvSFoIuT0+ief+jqCuwwAk= DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=mime-version:in-reply-to:references:date:message-id:subject:from:to :cc:content-type; b=VljHgvFcVZ5m+rY3GKXPvNhF7GwMAocoWmO94wM7KcH7iTXsSvZ5M4SRyTt5Hz5GJk yxKhC532Tzflt3m3C5p/2bHxi59cpkSDOESMv0zPRpcd/9Xy2SByHJwqHFXVpUfd3NeC y3bZ2VlVIFhSbpdSXvcAKtO2hTorNurqdVu8M= MIME-Version: 1.0 Received: by 10.216.93.66 with SMTP id k44mr4212782wef.67.1261751957734; Fri, 25 Dec 2009 06:39:17 -0800 (PST) In-Reply-To: References: <568624531.20091215163420@pyro.de> <957649379.20091216005253@pyro.de> <26F8D203-A923-47D3-9935-BE4BC6DA09B7@corp.spry.com> <1696529130.20091223212612@pyro.de> <1266543768.20091225120330@pyro.de> <982740779.20091225122331@pyro.de> Date: Fri, 25 Dec 2009 09:39:17 -0500 Message-ID: From: Thomas Burgess To: Wes Morgan Content-Type: text/plain; charset=ISO-8859-1 X-Content-Filtered-By: Mailman/MimeDel 2.1.5 Cc: freebsd-fs@freebsd.org Subject: Re: ZFS RaidZ2 with 24 drives? X-BeenThere: freebsd-fs@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Filesystems List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 25 Dec 2009 14:39:19 -0000 > I have my suspicions that this means your filesystem is heavily fragmented. I've had it happen to me on at least 3 pools, some of which were not even close to full, yet rebuilding the pool restored much of the performance. Hopefully with the block pointer rewrite support coming we will get some tools to address this. Right now I am not even aware of a tool that will check for fragmentation. I'm pretty sure he is running on a brand new pool. Originally he asked about creating a raidz2 vdev with 24 drives. Then, he said he "settled" for 2 12 drive vdevs. Also, this being FreeBSD it might be awhile before we even see the block pointer rewrite support even when it DOES hit.