From owner-svn-src-head@FreeBSD.ORG Wed Jul 22 11:34:05 2009 Return-Path: Delivered-To: svn-src-head@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 81CAC106564A; Wed, 22 Jul 2009 11:34:05 +0000 (UTC) (envelope-from mav@FreeBSD.org) Received: from cmail.optima.ua (cmail.optima.ua [195.248.191.121]) by mx1.freebsd.org (Postfix) with ESMTP id 408F38FC14; Wed, 22 Jul 2009 11:34:04 +0000 (UTC) (envelope-from mav@FreeBSD.org) Received: from orphanage.alkar.net (account mav@alkar.net [212.86.226.11] verified) by cmail.optima.ua (CommuniGate Pro SMTP 5.2.9) with ESMTPA id 249406272; Wed, 22 Jul 2009 14:33:58 +0300 Message-ID: <4A66F925.8000505@FreeBSD.org> Date: Wed, 22 Jul 2009 14:33:57 +0300 From: Alexander Motin User-Agent: Thunderbird 2.0.0.14 (X11/20080612) MIME-Version: 1.0 To: Erik Trulsson References: <200907220350.n6M3osaj030202@svn.freebsd.org> <4A66D0F4.4030108@FreeBSD.org> <4A66E9BE.2020603@FreeBSD.org> <20090722111608.GA97528@owl.midgard.homeip.net> In-Reply-To: <20090722111608.GA97528@owl.midgard.homeip.net> X-Enigmail-Version: 0.95.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Cc: Juli Mallett , svn-src-head@freebsd.org, svn-src-all@freebsd.org, src-committers@freebsd.org Subject: Re: svn commit: r195817 - head/usr.sbin/sysinstall X-BeenThere: svn-src-head@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: SVN commit messages for the src tree for head/-current List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 22 Jul 2009 11:34:06 -0000 Erik Trulsson wrote: > On Wed, Jul 22, 2009 at 01:28:14PM +0300, Alexander Motin wrote: >> Juli Mallett wrote: >>> On Wed, Jul 22, 2009 at 01:42, Alexander Motin wrote: >>>> Colin Percival wrote: >>>>> Remove the "dedicated disk mode" partitioning option from sysinstall, in >>>>> both the disk partitioning screen (the 'F' key) and via install.cfg (the >>>>> VAR_DEDICATED_DISK option). This functionality is currently broken in 8.x >>>>> due to libdisk and geom generating different partition names; this commit >>>>> merely acts to help steer users away from the breakage. >>>> Is there any other way to not align FS block to the ugly legacy 63 >>>> sectors per track boundary with sysinstall now? I think RAIDs won't be >>>> happy. May be it would be better to fix it? >>> If you're interested in fixing this issue, you might want to look at >>> the need for compatibility names so that existing DD installs aren't >>> broken, and so DD installs work as-is without correcting libdisk's >>> expectations about slice/partition names for DD disks, which is pretty >>> invasive, too. Not breaking new installs by not letting users install >>> broken systems is the absolute bare minimum approach, and given the >>> late date and the lack of movement on the kernel side, I've been >>> advocating for it for a while. >>> >>> See this message and others in the thread for some background: >>> >>> http://lists.freebsd.org/pipermail/freebsd-geom/2009-June/003567.html >> Sorry, ENOTIME. I am not advocating DD mode, it is really a hack. Offset >> 0 is just an easiest choice to align FS. Instead, I would really like >> sysinstall to honor real disk geometry instead of fake one. > > "real disk geometry" ? How would sysinstall find that? As I have said, GEOM is able to provide such info to user-level when provider reports it. > Keep in mind that any disk geometry reported by disks is completely fake > these days and is just an attempt to fit the total number of blocks into > the limitations of the PC BIOS. > > In short the whole notion of 'disk geometry' is mostly obsolete these days > and ought to be avoided as far as possible. You are right about regular HDDs, but I am speaking mostly about RAID geometry: stripe (native block) size and it's offset. geom_stripe provides that kind of information, and I believe most of hardware RAIDs could also do it. Also it could be used for different SSD/FLASH storages, which have media erase block of more then one sector. Proper FS alignment could reduce number of media erases. mmcsd(4) driver reports SD/MMC card's erase block size there. -- Alexander Motin