From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: <pve-devel-bounces@lists.proxmox.com> Received: from firstgate.proxmox.com (firstgate.proxmox.com [212.224.123.68]) by lore.proxmox.com (Postfix) with ESMTPS id 143DD1FF16E for <inbox@lore.proxmox.com>; Mon, 14 Apr 2025 16:35:39 +0200 (CEST) Received: from firstgate.proxmox.com (localhost [127.0.0.1]) by firstgate.proxmox.com (Proxmox) with ESMTP id A8C6535FDF; Mon, 14 Apr 2025 16:35:36 +0200 (CEST) Date: Mon, 14 Apr 2025 16:35:33 +0200 From: Wolfgang Bumiller <w.bumiller@proxmox.com> To: Fiona Ebner <f.ebner@proxmox.com> Message-ID: <hc6g2n3dw4hqmidefnlsnmmmrpqqbmf5ocy2jilgv4hlas3yan@bsru6bmxlzu6> References: <20250326142059.261938-1-m.carrara@proxmox.com> <20250326142059.261938-9-m.carrara@proxmox.com> <1743495535.spdhir37c5.astroid@yuna.none> <09a25015-f84c-4670-aad4-2ce3956189ad@proxmox.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <09a25015-f84c-4670-aad4-2ce3956189ad@proxmox.com> X-SPAM-LEVEL: Spam detection results: 0 AWL 0.082 Adjusted score from AWL reputation of From: address BAYES_00 -1.9 Bayes spam probability is 0 to 1% DMARC_MISSING 0.1 Missing DMARC policy KAM_DMARC_STATUS 0.01 Test Rule for DKIM or SPF Failure with Strict Alignment SPF_HELO_NONE 0.001 SPF: HELO does not publish an SPF Record SPF_PASS -0.001 SPF: sender matches SPF record Subject: Re: [pve-devel] [PATCH v1 pve-storage 8/8] pluginbase: document import and export methods X-BeenThere: pve-devel@lists.proxmox.com X-Mailman-Version: 2.1.29 Precedence: list List-Id: Proxmox VE development discussion <pve-devel.lists.proxmox.com> List-Unsubscribe: <https://lists.proxmox.com/cgi-bin/mailman/options/pve-devel>, <mailto:pve-devel-request@lists.proxmox.com?subject=unsubscribe> List-Archive: <http://lists.proxmox.com/pipermail/pve-devel/> List-Post: <mailto:pve-devel@lists.proxmox.com> List-Help: <mailto:pve-devel-request@lists.proxmox.com?subject=help> List-Subscribe: <https://lists.proxmox.com/cgi-bin/mailman/listinfo/pve-devel>, <mailto:pve-devel-request@lists.proxmox.com?subject=subscribe> Reply-To: Proxmox VE development discussion <pve-devel@lists.proxmox.com> Cc: Proxmox VE development discussion <pve-devel@lists.proxmox.com> Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Errors-To: pve-devel-bounces@lists.proxmox.com Sender: "pve-devel" <pve-devel-bounces@lists.proxmox.com> On Tue, Apr 01, 2025 at 11:40:14AM +0200, Fiona Ebner wrote: > Am 01.04.25 um 10:40 schrieb Fabian Gr=FCnbichler: > > On March 26, 2025 3:20 pm, Max Carrara wrote: > >> +=3Dhead3 $plugin->volume_export(\%scfg, $storeid, $fh, $volname, $for= mat [, $snapshot, $base_snapshot, $with_snapshots]) > >> + > >> +=3Dhead3 $plugin->volume_export(...) > >> + > >> +Exports a volume or a volume's C<$snapshot> into a file handle C<$fh>= as a > >> +stream with a desired export C<$format>. See L<FORMATS> for all impor= t/export > >> +formats. > >> + > >> +Optionally, C<$snapshot> (if provided) may have a C<$base_snapshot>, = and > >> +C<$with_snapshots> states whether the volume has snapshots overall. > > = > > this is incomplete/wrong > > = > > $with_snapshots means the export should include snapshots, not whether > > the volume has snapshots.. > > $snapshot means "this is the snapshot to export" if only exporting the > > snapshot ($with_snapshots =3D=3D 0), or "this is the *last* snapshot ex= port" > > if exporting a stream of snapshots ($with_snapshots =3D=3D 1) > > $base_snapshot means "this is the start of the snapshot range to export" > > (i.e., do an incremental export on top of this base) > > = > > this is mostly only relevant for zfs at the moment (other storages can > > either export a volume including its snapshots, or just the volume, but > > no complicated incremental streams of snapshots), but will change once > > we implement replication export/import for other storages.. > = > There are already ideas floating around to change this and add proper > format negotiation. We'll also need to ask the target what it supports > like for remote migration, the sending side cannot really know that. And > as part of that change from the confusing set of snapshot-related > parameters to having an actual "what kind of transport" enum: > 1. current data (of an image or a snapshot) > 2. full sync with all snapshots > 3. incremental stream > No details worked out yet though and not really relevant for documenting > the status quo. > = > >> +Optionally, C<$snapshot> (if provided) may have a C<$base_snapshot>, = and > >> +C<$with_snapshots> states whether the volume has snapshots overall. R= enaming an > >> +existing volume may also optionally be allowed via C<$allow_rename> > > = > > see above, but here $snapshot is mainly there to have the same > > arguments for volume_import_formats so a plugin can have a single > > implementation, not because it is used anywhere IIRC.. > = > The LVMPlugin.pm and Plugin.pm do have different implementations of the > volume_{export,import}_formats() methods, precisely because they need to > ignore the $snapshot parameter for the import case. Yes, we do pass the > same arguments, but it can only matter for the "incremental stream" > scenario. Otherwise, the parameter has nothing to do with the import > side. Here it would also be much nicer to have an actual "what kind of > transport" parameter. Actually, 'btrfs' format for btrfs-send/recv uses the snapshot name in both import & export cases: - We receive into a temporary directory - BTRFS does not allow moving read-only snapshots into different directories, but we need the final one to also be the current writable state, so: - We remove the read-only flag. - We exchange it with the current sate. - We take a "snapshot" to reproduce the that last `$snapshot`. - We clean up. It's a bit awkward. But that's just BTRFS... _______________________________________________ pve-devel mailing list pve-devel@lists.proxmox.com https://lists.proxmox.com/cgi-bin/mailman/listinfo/pve-devel