From owner-freebsd-current Sun Nov 24 21:11:48 2002 Delivered-To: freebsd-current@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id 3DFBE37B401; Sun, 24 Nov 2002 21:11:47 -0800 (PST) Received: from beastie.mckusick.com (beastie.mckusick.com [209.31.233.184]) by mx1.FreeBSD.org (Postfix) with ESMTP id D373343E6E; Sun, 24 Nov 2002 21:11:46 -0800 (PST) (envelope-from mckusick@beastie.mckusick.com) Received: from beastie.mckusick.com (localhost [127.0.0.1]) by beastie.mckusick.com (8.12.3/8.12.3) with ESMTP id gAP5BU59067794; Sun, 24 Nov 2002 21:11:30 -0800 (PST) (envelope-from mckusick@beastie.mckusick.com) Message-Id: <200211250511.gAP5BU59067794@beastie.mckusick.com> To: current@freebsd.org Subject: Update to UFS2 Superblock Format Cc: Robert Watson , re@freebsd.org X-URL: http://WWW.McKusick.COM/ Reply-To: Kirk McKusick Date: Sun, 24 Nov 2002 21:11:30 -0800 From: Kirk McKusick Sender: owner-freebsd-current@FreeBSD.ORG Precedence: bulk List-ID: List-Archive: (Web Archive) List-Help: (List Instructions) List-Subscribe: List-Unsubscribe: X-Loop: FreeBSD.ORG On Tuesday Nov 26th I plan to make an update to the UFS2 superblock. It will not affect UFS1 filesystems so should be generally transparent to most -current users. For those using UFS2 filesystems, the new kernel will update the superblock to the new format the first time that your UFS2 filesystem is mounted read-write. Once updated it will not be able to be mounted by older kernels unless the `zapsb' program (see below) is run to revert it to the old format. The only really noticable problem arises when you are booting from a UFS2 root partition. Here, you must follow the following steps: 1) boot new kernel 2) mount -u / 3) install new bootstrap Once the new kernel has converted the filesystem format for the root partition, the old bootstrap will no longer recognize it, so if you do not have a new bootstrap, you will no longer be able to boot from it. Note that you cannot update to the new bootstrap until the filesystem has been converted as the new bootstrap will not recognize the old superblock format. Again, this change will only affect you if you are using a UFS2 filesystem as your root filesystem. The changes that I plan to apply can be viewed at: http://www.freebsd.org/~mckusick/UFS2_update.diffs The program `zapsb.c' that reverts a UFS2 filesystem to its previous state can be found at: http://www.freebsd.org/~mckusick/zapsb.c If this change is going to cause you undue hardship, please send me mail (mckusick@mckusick.com). Kirk McKusick To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-current" in the body of the message