From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: <d.tschlatscher@proxmox.com> Received: from firstgate.proxmox.com (firstgate.proxmox.com [212.224.123.68]) (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 lists.proxmox.com (Postfix) with ESMTPS id 88FDB91FE9 for <pbs-devel@lists.proxmox.com>; Mon, 10 Oct 2022 16:38:16 +0200 (CEST) Received: from firstgate.proxmox.com (localhost [127.0.0.1]) by firstgate.proxmox.com (Proxmox) with ESMTP id 635705486 for <pbs-devel@lists.proxmox.com>; Mon, 10 Oct 2022 16:38:16 +0200 (CEST) Received: from proxmox-new.maurer-it.com (proxmox-new.maurer-it.com [94.136.29.106]) (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 firstgate.proxmox.com (Proxmox) with ESMTPS for <pbs-devel@lists.proxmox.com>; Mon, 10 Oct 2022 16:38:15 +0200 (CEST) Received: from proxmox-new.maurer-it.com (localhost.localdomain [127.0.0.1]) by proxmox-new.maurer-it.com (Proxmox) with ESMTP id BFD4D44912 for <pbs-devel@lists.proxmox.com>; Mon, 10 Oct 2022 16:38:14 +0200 (CEST) Message-ID: <9bbaf5a1-0878-9c3b-f46c-2e96f93a7c97@proxmox.com> Date: Mon, 10 Oct 2022 16:38:13 +0200 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:102.0) Gecko/20100101 Thunderbird/102.3.0 Content-Language: en-US To: pbs-devel@lists.proxmox.com References: <20221007115449.3562604-1-d.csapak@proxmox.com> <20221007115449.3562604-5-d.csapak@proxmox.com> From: Daniel Tschlatscher <d.tschlatscher@proxmox.com> In-Reply-To: <20221007115449.3562604-5-d.csapak@proxmox.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit X-SPAM-LEVEL: Spam detection results: 0 AWL 1.821 Adjusted score from AWL reputation of From: address BAYES_00 -1.9 Bayes spam probability is 0 to 1% KAM_DMARC_STATUS 0.01 Test Rule for DKIM or SPF Failure with Strict Alignment NICE_REPLY_A -3.934 Looks like a legit reply (A) SPF_HELO_NONE 0.001 SPF: HELO does not publish an SPF Record SPF_PASS -0.001 SPF: sender matches SPF record Subject: Re: [pbs-devel] [PATCH proxmox-backup v2 4/5] docs: add documentation about the 'sync-level' tuning X-BeenThere: pbs-devel@lists.proxmox.com X-Mailman-Version: 2.1.29 Precedence: list List-Id: Proxmox Backup Server development discussion <pbs-devel.lists.proxmox.com> List-Unsubscribe: <https://lists.proxmox.com/cgi-bin/mailman/options/pbs-devel>, <mailto:pbs-devel-request@lists.proxmox.com?subject=unsubscribe> List-Archive: <http://lists.proxmox.com/pipermail/pbs-devel/> List-Post: <mailto:pbs-devel@lists.proxmox.com> List-Help: <mailto:pbs-devel-request@lists.proxmox.com?subject=help> List-Subscribe: <https://lists.proxmox.com/cgi-bin/mailman/listinfo/pbs-devel>, <mailto:pbs-devel-request@lists.proxmox.com?subject=subscribe> X-List-Received-Date: Mon, 10 Oct 2022 14:38:16 -0000 Through Matthias' answer I noticed 3 more NITs On 10/7/22 13:54, Dominik Csapak wrote: > Signed-off-by: Dominik Csapak <d.csapak@proxmox.com> > --- > docs/storage.rst | 36 ++++++++++++++++++++++++++++++++++++ > 1 file changed, 36 insertions(+) > > diff --git a/docs/storage.rst b/docs/storage.rst > index 1909bd84..d7e19ec1 100644 > --- a/docs/storage.rst > +++ b/docs/storage.rst > @@ -338,3 +338,39 @@ and only available on the CLI: > > # proxmox-backup-manager datastore update <storename> --tuning 'chunk-order=none' > > +* ``sync-level``: Datastore fsync level: > + > + You can set the level of syncing on the datastore for chunks, which influences > + the crash resistancy of backups in case of a powerloss or hard shutoff. Typo: resistance > + There are currently three levels: > + > + - `none` (default): Does not do any syncing when writing chunks. This is fast > + and normally ok, since the kernel eventually flushes writes onto the disk. > + The kernel sysctls `dirty_expire_centisecs` and `dirty_writeback_centisecs` > + are used to tune that behaviour, while the default is to flush old data > + after ~30s. > + > + - `filesystem` : This triggers a ``syncfs(2)`` after a backup, but before > + the task returns `OK`. This way it is ensured that the written backups > + are on disk. This is a good balance between speed and consistency,. There seems to be a rogue comma after consistency > + Note that the underlying storage device sitll needs to protect itself against > + powerloss to flush its internal ephemeral caches to the permanent storage layer. > + > + - `file` With this mode, a fsync is triggered on every chunk insertion, which > + makes sure each and every chunk reaches the disk as soon as possible. While > + this reaches the hightest level of consistency, for many storages (especially > + slower ones) this comes at the cost of speed. For many users the `filesystem` > + mode is better suited, but for very fast storages this mode can be ok. > + > + This can be set with: > + > +.. code-block:: console > + > + # proxmox-backup-manager datastore update <storename> --tuning 'sync-level=filesystem' > + > +If you want to set multiple tuning options simultaniously, you can seperate them Typo: separate > +with a comma, like this: > + > +.. code-block:: console > + > + # proxmox-backup-manager datastore update <storename> --tuning 'sync-level=filesystem,chunk-order=none'