From owner-freebsd-questions@freebsd.org Tue Apr 18 01:28:41 2017 Return-Path: Delivered-To: freebsd-questions@mailman.ysv.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:1900:2254:206a::19:1]) by mailman.ysv.freebsd.org (Postfix) with ESMTP id 6FA6BD43934 for ; Tue, 18 Apr 2017 01:28:41 +0000 (UTC) (envelope-from mueller6722@twc.com) Received: from dnvrco-oedge-vip.email.rr.com (dnvrco-outbound-snat.email.rr.com [107.14.73.225]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client CN "dnvrco-oedge-vip.email.rr.com", Issuer "dnvrco-oedge-vip.email.rr.com" (not verified)) by mx1.freebsd.org (Postfix) with ESMTPS id 4E681F49 for ; Tue, 18 Apr 2017 01:28:40 +0000 (UTC) (envelope-from mueller6722@twc.com) Received: from [74.134.208.22] ([74.134.208.22:62557] helo=localhost) by dnvrco-omsmta03 (envelope-from ) (ecelerity 3.6.9.48312 r(Core:3.6.9.0)) with ESMTP id 96/0D-25473-6CB65F85; Tue, 18 Apr 2017 01:28:39 +0000 Date: Tue, 18 Apr 2017 01:28:33 +0000 Message-ID: <96.0D.25473.6CB65F85@dnvrco-omsmta03> From: "Thomas Mueller" To: freebsd-questions@freebsd.org Subject: Re: Is it possible to install FreeBSD on a single MBR slice with ZFS ? References: <20170418014946.fa114b49.freebsd@edvax.de> X-RR-Connecting-IP: 107.14.64.88:25 X-BeenThere: freebsd-questions@freebsd.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: User questions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 18 Apr 2017 01:28:41 -0000 (snip) > > But following the migration, I have made a serious error. I used > > Windows (ada0s1) to delete ada0s2 : > > Windows has rearranged the MBR table to make ada0s3 -> ada0s2. > Sounds like something OS/2 has done to me many years ago. :-) > > I am now struggling to fix the MBR table. > Of course. > > If you have any tips, that shall be wonderful > Do not and never use "Windows" to deal with lower level aspects of > your disk. It will for sure mess things up, and in worst case, you > need to reinstall everything from scratch. Of course you don't, as > you have a working backup you can rely on. ;-) > It's not as easy anymore to fix partition table entries with a simple > handheld calculator and "Norton Disk Editor" started from a handy DOS > boot floppy. :-) > For the future: Bootable CDs like UBCD or PartEd Magic provice > excellent tools to deal with re-partitioning. You can use FreeBSD's > editor as well, especially if all you want to do is delete some > MBR slices. It's the first thing you do in the installer, then > follow to create new slices as you need them, and go on with the > installation process. > Polytropon With either gpart or Rod Smith's gdisk, and I believe also NetBSD's gpt, you can save the GPT partition table data to a file, preferably on a different disk, such as a USB stick, and restore if the GPT partition table is damaged. Backup partition-table data file would have to be restored from the same partitioning software. This requires a USB-stick or other off-disk installation of FreeBSD that would include gpart or gdisk; gdisk also can be used under Linux. This would be better than Norton Disk Editor + handheld calculator + DOS boot floppy. Your mention of OS/2 reminds me that this month, or about 10 days ago, marks the sixteenth anniversary of the crash with OS/2 Warp 4. On rebooting, OS/2 CHKDSK ran automatically and ran amok, trashing all data on my second hard drive in addition to partition data on the smaller, first hard drive. I was never able to boot OS/2 again, even from maintenance or installation floppies, result was Trap 000e or Trap 000c. I believe OS/2 Warp 4 had better hardware support than FreeBSD or NetBSD back then, 16 years ago, but since then OS/2 and its successor, eComStation, have not kept up, and now FreeBSD and NetBSD seem to be far ahead of eComStation. Tom