From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-3.7 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id F2A32C433E0 for ; Mon, 21 Dec 2020 17:38:10 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id BBC2A22ADF for ; Mon, 21 Dec 2020 17:38:10 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1725882AbgLURho (ORCPT ); Mon, 21 Dec 2020 12:37:44 -0500 Received: from rin.romanrm.net ([51.158.148.128]:59046 "EHLO rin.romanrm.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725804AbgLURho (ORCPT ); Mon, 21 Dec 2020 12:37:44 -0500 Received: from natsu (unknown [IPv6:fd39::e99e:8f1b:cfc9:ccb8]) by rin.romanrm.net (Postfix) with SMTP id DF1CA848; Mon, 21 Dec 2020 17:37:01 +0000 (UTC) Date: Mon, 21 Dec 2020 22:37:01 +0500 From: Roman Mamedov To: Remi Gauvin Cc: Claudius Ellsel , linux-btrfs Subject: Re: WG: How to properly setup for snapshots Message-ID: <20201221223701.0845e9ad@natsu> In-Reply-To: References: MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-btrfs@vger.kernel.org On Mon, 21 Dec 2020 12:05:37 -0500 Remi Gauvin wrote: > I suggest making a new Read/Write subvolume to put your snapshots into > > btrfs subvolume create .my_snapshots > btrfs subvolume snapshot -r /mnt_point /mnt_point/.my_snapshots/snapshot1 It sounds like this could plant a misconception right from the get go. You don't really put snapshot* "into" a subvolume. Subvolumes do not actually contain other subvolumes, since making a snapshot of the "parent" won't include any content of the subvolumes with pathnames below it. As such there's no benefit in storing snapshots "inside" a subvolume. There's not much of the "inside". Might as well just create a regular directory for that -- and with less potential for confusion. * - keep in mind that "snapshot" and "subvolume" mean the same thing in Btrfs, the only difference being that "snapshot"-subvolume started its life as being a full copy(-on-write) of some other subvolume. -- With respect, Roman