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 TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by finch.gentoo.org (Postfix) with ESMTPS id 34CC2158017 for ; Thu, 30 Sep 2021 17:19:23 +0000 (UTC) Received: from pigeon.gentoo.org (localhost [127.0.0.1]) by pigeon.gentoo.org (Postfix) with SMTP id 10E00E0880; Thu, 30 Sep 2021 17:19:16 +0000 (UTC) Received: from smtp.hosts.co.uk (smtp.hosts.co.uk [85.233.160.19]) (using TLSv1.2 with cipher ECDHE-RSA-CHACHA20-POLY1305 (256/256 bits)) (No client certificate requested) by pigeon.gentoo.org (Postfix) with ESMTPS id A4C51E0870 for ; Thu, 30 Sep 2021 17:19:15 +0000 (UTC) Received: from host86-157-192-80.range86-157.btcentralplus.com ([86.157.192.80] helo=[192.168.1.65]) by smtp.hosts.co.uk with esmtpa (Exim) (envelope-from ) id 1mVziD-000BTg-8v for gentoo-user@lists.gentoo.org; Thu, 30 Sep 2021 18:19:14 +0100 Subject: Re: [gentoo-user] How to compress lots of tarballs To: gentoo-user@lists.gentoo.org References: <5513654.DvuYhMxLoT@wstn> <3138453.44csPzL39Z@wstn> <4687348.31r3eYUQgx@wstn> <46a2a568-575a-49be-a16b-5c2d59faee54@gmail.com> <0aa6539b-958f-53f9-a6a2-ad5e984a0d85@youngman.org.uk> From: antlists Message-ID: Date: Thu, 30 Sep 2021 18:19:14 +0100 User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:78.0) Gecko/20100101 Thunderbird/78.14.0 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 In-Reply-To: Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-GB Content-Transfer-Encoding: 7bit X-Archives-Salt: 51178c5f-6290-4b3a-a5c5-f99b65149e6a X-Archives-Hash: a0925c8796ad118d9c9e4904d22f486b On 30/09/2021 00:17, Rich Freeman wrote: > On Wed, Sep 29, 2021 at 5:48 PM Wols Lists wrote: >> An LVM snapshot creates a "copy on write" image. I'm just beginning to >> dig into it myself, but I agree it's a bit confusing. > So, snapshots in general are a solution for making backups atomic. > That is, they allow a backup to look as if the entire backup was taken > in an instant. > > The simplest way to accomplish that is via offline backups. Unmount > the drive, mount it read-only, then perform a backup. That guarantees > that nothing changes between the time the backup starts/stops. Of > course, it also can mean that for many hours you can't really use the > drive. > > Snapshots let you cheat. They create two views of the drive - one > that can be used normally, and one which is a moment-in-time snapshot > of what the drive looked like. You backup the snapshot, and you can > use the regular drive. Yup. I'm planning to configure systemd to do most of this for me. As a desktop system it goes up and down, so the plan is a trigger will fire midnight fri/sat, and the first time it gets booted after that, a snapshot will be taken before fstab is run. Then I'll have backups of /home and /. I won't keep many root backups, but I'll keep /home until I run out of space. And that's why I suggested if you want a separate backup rather than a collection of snapshots, you snapshot the backup and use in-place rsync. Of course that still means you need to quiesce the bit you're copying, but you could back it up piecemeal. Cheers, Wol