From owner-freebsd-current@FreeBSD.ORG Sat Apr 4 16:09:58 2009 Return-Path: Delivered-To: freebsd-current@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id E9226106564A for ; Sat, 4 Apr 2009 16:09:58 +0000 (UTC) (envelope-from xcllnt@mac.com) Received: from asmtpout017.mac.com (asmtpout017.mac.com [17.148.16.92]) by mx1.freebsd.org (Postfix) with ESMTP id C643E8FC12 for ; Sat, 4 Apr 2009 16:09:58 +0000 (UTC) (envelope-from xcllnt@mac.com) MIME-version: 1.0 Content-transfer-encoding: 7BIT Content-type: text/plain; charset=US-ASCII; format=flowed; delsp=yes Received: from MacBook-Pro.lan.xcllnt.net (mail.xcllnt.net [75.101.29.67]) by asmtp017.mac.com (Sun Java(tm) System Messaging Server 6.3-8.01 (built Dec 16 2008; 32bit)) with ESMTPSA id <0KHL00DXD3KKWP40@asmtp017.mac.com> for freebsd-current@freebsd.org; Sat, 04 Apr 2009 09:09:56 -0700 (PDT) Message-id: <42E3BB6C-16C7-4211-A4FD-A362383418E9@mac.com> From: Marcel Moolenaar To: Tai-hwa Liang In-reply-to: <09040423143118.91304@www.mmlab.cse.yzu.edu.tw> Date: Sat, 04 Apr 2009 09:09:55 -0700 References: <20090331155542.74d89d64@ernst.jennejohn.org> <60084D1E-9F64-463A-A8E9-7A237D5C7661@mac.com> <0904011910169.29800@www.mmlab.cse.yzu.edu.tw> <0904020940371.36257@www.mmlab.cse.yzu.edu.tw> <4CCDEFD6-830E-4C8F-B7A2-B7878F8842BE@mac.com> <0904021314574.37737@www.mmlab.cse.yzu.edu.tw> <09040309313414.76643@www.mmlab.cse.yzu.edu.tw> <0904031327195.78401@www.mmlab.cse.yzu.edu.tw> <8583A3BA-2871-4DF4-9792-1031044A4A22@mac.com> <09040315161311.79260@www.mmlab.cse.yzu.edu.tw> <1DDB4728-7742-4265-999F-F1A0FC69F9E4@mac.com> <0904040858433.86299@www.mmlab.cse.yzu.edu.tw> <7AD352A2-BEDD-4DFD-896D-104E6376D887@mac.com> <09040411131618.87313@www.mmlab.cse.yzu.edu.tw> <09040423143118.91304@www.mmlab.cse.yzu.edu.tw> X-Mailer: Apple Mail (2.930.3) Cc: freebsd-current@freebsd.org Subject: Re: Removal of GEOM_BSD, GEOM_MBR, GEOM_PC98 and GEOM_SUNLABEL X-BeenThere: freebsd-current@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Discussions about the use of FreeBSD-current List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sat, 04 Apr 2009 16:09:59 -0000 On Apr 4, 2009, at 8:16 AM, Tai-hwa Liang wrote: > I have to use ad0s7 after moving to GEOM_PART_{BSD,EBR,MBR}; > otherwise, > booting with with /dev/ad0s7a looks like: > Can't stat /dev/ad0s7a: No such file or directory It just hit me (doh!). The problem is that /dev/ad0s7 is a compatibility symlink, which exists outside of the GEOM graph. That is, it's a symlink that geom_dev creates and it provides an alternate name to the same "entry point". In your case another GEOM (gpart for the BSD scheme) is stacked onto the gpart GEOM for the EBR scheme) -- with possibly other GEOMs in between. The provider for the 'a' partition is named based on the underlying consumer, which is based on the true name of the GEOM: "ad0s3+00103bf1a". There's no alias for the device node that corresponds to this GEOM and based on some alias that was created by some other geom_dev. This is simply not possible to without messing things up pretty easily. In short: the solution of using a compatibility symlink is flawed at best and useless in the worst case. There's no software fix for it. I think we're left with a simple choice: 1) have EBR create the "old" names and tell the user to reboot every time they make a change in FreeBSD and when booting into FreeBSD after the EBR changed, boot into single user mode to change /etc/fstab and *then* go into multi-user mode, or 2) stick with the new names and tell the user to make this one-time adjustment during upgrades and that's it. If we choose 2, we can argue whether to keep the symlinks or not. I'm sure there's a small group of people for which it works, but I fear the majority of people still have problems. Any thoughts? -- Marcel Moolenaar xcllnt@mac.com