From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.jrs-s.net ([173.230.137.22]:33326 "EHLO mail.jrs-s.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754517AbaAFTbS (ORCPT ); Mon, 6 Jan 2014 14:31:18 -0500 Received: from [192.168.0.50] (mail.coastalscience.com [66.83.151.234]) (using TLSv1 with cipher ECDHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) (Authenticated sender: jim@jrs-s.net) by mail.jrs-s.net (Postfix) with ESMTPSA id 6C5D5D2A4 for ; Mon, 6 Jan 2014 14:31:17 -0500 (EST) Message-ID: <52CB0484.8030806@jrs-s.net> Date: Mon, 06 Jan 2014 14:31:16 -0500 From: Jim Salter MIME-Version: 1.0 To: linux-btrfs Subject: correct way to rollback a root filesystem? References: <52C73987.7000106@jrs-s.net> <52C87A41.9030701@jrs-s.net> <05C97109-682D-4A62-B074-4EDCF8E9CE1E@colorremedies.com> <1416119.lWHlh5idGF@quad> In-Reply-To: Content-Type: text/plain; charset=ISO-8859-1; format=flowed Sender: linux-btrfs-owner@vger.kernel.org List-ID: Hi list - I tried a kernel upgrade with moderately disastrous (non-btrfs-related) results this morning; after the kernel upgrade Xorg was completely borked beyond my ability to get it working properly again through any normal means. I do have hourly snapshots being taken by cron, though, so I'm successfully X'ing again on the machine in question right now. It was quite a fight getting back to where I started even so, though - I'm embarassed to admit I finally ended up just doing a cp --reflink=all /mnt/@/.snapshots/snapshotname /mnt/@/ from the initramfs BusyBox prompt. Which WORKED well enough, but obviously isn't ideal. I tried the btrfs sub set-default command - again from BusyBox - and it didn't seem to want to work for me; I got an inappropriate ioctl error (which may be because I tried to use / instead of /mnt, where the root volume was CURRENTLY mounted, as an argument?). Before that, I'd tried setting subvol=@root (which is the writeable snapshot I created from the original read-only hourly snapshot I had) in GRUB and in fstab... but that's what landed me in BusyBox to begin with. When I DID mount the filesystem in BusyBox on /mnt, I saw that @ and @home were listed under /mnt, but no other "directories" were - which explains why mounting -o subvol=@root didn't work. I guess the question is, WHY couldn't I see @root in there, since I had a working, readable, writeable snapshot which showed its own name as "root" when doing a btrfs sub show /.snapshots/root ? Thanks.