From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from lists.gentoo.org (pigeon.gentoo.org [208.92.234.80]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits)) (No client certificate requested) by finch.gentoo.org (Postfix) with ESMTPS id 2266F15815E for ; Sun, 11 Feb 2024 10:48:43 +0000 (UTC) Received: from pigeon.gentoo.org (localhost [127.0.0.1]) by pigeon.gentoo.org (Postfix) with SMTP id 0D73DE2A4C; Sun, 11 Feb 2024 10:48:37 +0000 (UTC) Received: from mail.muc.de (mail.muc.de [193.149.48.3]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256) (No client certificate requested) by pigeon.gentoo.org (Postfix) with ESMTPS id 5FF99E2A34 for ; Sun, 11 Feb 2024 10:48:35 +0000 (UTC) Received: (qmail 23235 invoked by uid 3782); 11 Feb 2024 11:48:34 +0100 Received: from acm.muc.de (pd953a1b2.dip0.t-ipconnect.de [217.83.161.178]) (using STARTTLS) by colin.muc.de (tmda-ofmipd) with ESMTP; Sun, 11 Feb 2024 11:48:33 +0100 Received: (qmail 5487 invoked by uid 1000); 11 Feb 2024 10:48:33 -0000 Date: Sun, 11 Feb 2024 10:48:33 +0000 To: gentoo-user@lists.gentoo.org Subject: Re: [gentoo-user] Don't be like stupid me! Message-ID: References: Precedence: bulk List-Post: List-Help: List-Unsubscribe: List-Subscribe: List-Id: Gentoo Linux mail X-BeenThere: gentoo-user@lists.gentoo.org Reply-to: gentoo-user@lists.gentoo.org X-Auto-Response-Suppress: DR, RN, NRN, OOF, AutoReply MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: X-Submission-Agent: TMDA/1.3.x (Ph3nix) From: Alan Mackenzie X-Primary-Address: acm@muc.de X-Archives-Salt: 810ef1c5-c983-4cf5-a530-215ec29802a7 X-Archives-Hash: 67953bab9507ba69f7b9e6e5e0a6cae5 Hello, Bill. On Sun, Feb 11, 2024 at 10:14:49 +0800, William Kenworthy wrote: > On 10/2/24 23:56, Alan Mackenzie wrote: > > I was wanting to do a pretty full build of my Emacs working repository. > > This involved first purging al *.elc files. The way to do this is > > $ find . -name '*.elc' | xargs rm > > . But for some reason, I typed > > $ find . '*.elc' | xargs rm > > . I even carefully checked it before pressing RET. However, press it I > > did, instantly deleting all files in my working directory. OUTCH! > > So, I fell back on my backup from last Sunday. After about 1½ hours > > trial and error, I had my source files as of last Sunday back again, > > though git could have been more helpful than it actually is. > > Thankfully, I had Emacs open, with all the files modified since Sunday > > in buffers. So, I laboriously worked through Emacs's buffer list, > > saving those ones I'd since changed. > > I lost all my timestamps on the files, and lost all my Emacs backup > > files (things ending in ~ which Emacs constantly makes). But my > > software builds and runs. > > It could have been a lot worse. Boys and girls, don't use > > $ find .... | xargs rm > > unless you really know what you're doing. And even then, it's probably > > better not to. ;-( > > It occurred to me fairly quickly after that press of RET that I could > > have done well with a COW snapshot facility, something which has been > > discussed at length on another recent thread. I even have LVM on my > > machine for its RAID capabilities. But I've never bothered before. I > > mean "I'm too careful", amn't I? ;-( At least I do a weekly backup, > > though. > > So, in the end I managed to recover fairly well, thankfully. > No, you don't need a snapshot system - you need a proper backup system > that stores the proper metadata. I remembered after sending my original post that I stored the timestamps of all the files in a file called timestamps.txt. So a quick sed script invocation on this file, and I had my timestamps back again! > When I was experimenting with snapshots (btrfs and moosefs) at > different times I lost everything a few times with filesystem > corruption which meant I lost the snapshots too. > Snapshots are NOT safe backups - treat them as a convenient copy ... I was thinking of a snapshot more as an addition to backups, not an alternative. Such would have made it easier for me to recover yesterday. A backup on the same medium as the filesystem isn't a backup at all. I've never had a disk drive or SSD fail on me yet, but I'm not pushing my luck. > BillK -- Alan Mackenzie (Nuremberg, Germany).