From owner-freebsd-stable@FreeBSD.ORG Thu Jul 22 04:29:55 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 4C5F2106564A for ; Thu, 22 Jul 2010 04:29:55 +0000 (UTC) (envelope-from amvandemore@gmail.com) Received: from mail-yw0-f54.google.com (mail-yw0-f54.google.com [209.85.213.54]) by mx1.freebsd.org (Postfix) with ESMTP id 042FB8FC14 for ; Thu, 22 Jul 2010 04:29:54 +0000 (UTC) Received: by ywf9 with SMTP id 9so1083960ywf.13 for ; Wed, 21 Jul 2010 21:29:54 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma; h=domainkey-signature:mime-version:received:received:in-reply-to :references:date:message-id:subject:from:to:cc:content-type; bh=zxsRPqwvZIINBnC9RGVxwiMUnDkJXf4cBroTEkcHL70=; b=IBaIlHDgkMvNPq7LBlGa1bEnFkt/tj5CC61AZxpbNcaw47g4ezGp9tBaSKkJ5ZbaP6 XhF434+C53tOENQ2pEFM2SlJ9iAEus0mOakx4rPupfq3HJ7QPMUE9K2yJcFUmv74VM9r oM9YcB+LjQkoIDPUY+Hk9ncK+eloM/UP67l5U= 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=YC1nX8t+4uaiv83hi6vBRSEg+SmFN0yjfHpeLnWN+5wflIMge+Xo8QnzViU8aSW6Ml Zh/kDe78zt5NlO+e34fADQ5dQ1U+i3ovPSfPGHeDO0DX8E4iJijyqeLNcVzRneN49Zaq VSZQIMEYRlRZnRN7jRRrH4/NoazDNWCzEyis8= MIME-Version: 1.0 Received: by 10.224.100.144 with SMTP id y16mr897207qan.76.1279772994177; Wed, 21 Jul 2010 21:29:54 -0700 (PDT) Received: by 10.229.29.71 with HTTP; Wed, 21 Jul 2010 21:29:54 -0700 (PDT) In-Reply-To: References: <4C47B57F.5020309@langille.org> Date: Wed, 21 Jul 2010 23:29:54 -0500 Message-ID: From: Adam Vande More To: Charles Sprickman Content-Type: text/plain; charset=ISO-8859-1 X-Content-Filtered-By: Mailman/MimeDel 2.1.5 Cc: freebsd-stable , Dan Langille Subject: Re: Using GTP and glabel for ZFS arrays 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: Thu, 22 Jul 2010 04:29:55 -0000 On Wed, Jul 21, 2010 at 11:20 PM, Charles Sprickman wrote: > > -Does it only affect the new drives with 4K blocks? > No, although blocksize does effect these symptoms > -If it does not, is it generally good to start your first partition at 1MB > in? How exactly does doing this "fix" the alignment issue? To be clear, we are talking about data partitions, not the boot one. Difficult for me to explain concisely, but basically it has to do with seek time. A mis-aligned partition will almost always have an extra seek for each standard seek you'd have on aligned one. There have been some discussions about in the archives, also this is not unique to FreeBSD so google will have a more detailed and probably better explanation. > I assume the same can be applied if you do boot from zfs; you'd still > create the "freebsd-boot" partition starting at 34, but your next partition > (be it swap or zfs) would start either 512 or 1024 sectors in? > Yes. -- Adam Vande More