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 [IPv6:2a01:7e0:0:424::9]) by lore.proxmox.com (Postfix) with ESMTPS id 32BD51FF16E for <inbox@lore.proxmox.com>; Mon, 3 Feb 2025 12:15:37 +0100 (CET) Received: from firstgate.proxmox.com (localhost [127.0.0.1]) by firstgate.proxmox.com (Proxmox) with ESMTP id 6682D2DA74; Mon, 3 Feb 2025 12:15:36 +0100 (CET) From: Alexander Abraham <a.abraham@proxmox.com> To: pve-devel@lists.proxmox.com Date: Mon, 3 Feb 2025 12:14:47 +0100 Message-Id: <20250203111448.80291-2-a.abraham@proxmox.com> X-Mailer: git-send-email 2.39.5 In-Reply-To: <20250203111448.80291-1-a.abraham@proxmox.com> References: <20250203111448.80291-1-a.abraham@proxmox.com> MIME-Version: 1.0 X-SPAM-LEVEL: Spam detection results: 0 AWL -0.314 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_ASCII_DIVIDERS 0.8 Email that uses ascii formatting dividers and possible spam tricks 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 URIBL_SBL_A 0.1 Contains URL's A record listed in the Spamhaus SBL blocklist [185.199.108.153, 185.199.111.153, 185.199.110.153] Subject: [pve-devel] [PATCH pve-docs v2 1/2] Section on ZFS and swap corrected. 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: Alexander Abraham <a.abraham@proxmox.com> Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Errors-To: pve-devel-bounces@lists.proxmox.com Sender: "pve-devel" <pve-devel-bounces@lists.proxmox.com> --- local-zfs.adoc | 36 +----------------------------------- 1 file changed, 1 insertion(+), 35 deletions(-) diff --git a/local-zfs.adoc b/local-zfs.adoc index c64fb27..bcd02f7 100644 --- a/local-zfs.adoc +++ b/local-zfs.adoc @@ -627,41 +627,7 @@ You *must reboot* to activate these changes. SWAP on ZFS ~~~~~~~~~~~ -Swap-space created on a zvol may generate some troubles, like blocking the -server or generating a high IO load, often seen when starting a Backup -to an external Storage. - -We strongly recommend to use enough memory, so that you normally do not -run into low memory situations. Should you need or want to add swap, it is -preferred to create a partition on a physical disk and use it as a swap device. -You can leave some space free for this purpose in the advanced options of the -installer. Additionally, you can lower the -``swappiness'' value. A good value for servers is 10: - ----- -# sysctl -w vm.swappiness=10 ----- - -To make the swappiness persistent, open `/etc/sysctl.conf` with -an editor of your choice and add the following line: - --------- -vm.swappiness = 10 --------- - -.Linux kernel `swappiness` parameter values -[width="100%",cols="<m,2d",options="header"] -|=========================================================== -| Value | Strategy -| vm.swappiness = 0 | The kernel will swap only to avoid -an 'out of memory' condition -| vm.swappiness = 1 | Minimum amount of swapping without -disabling it entirely. -| vm.swappiness = 10 | This value is sometimes recommended to -improve performance when sufficient memory exists in a system. -| vm.swappiness = 60 | The default value. -| vm.swappiness = 100 | The kernel will swap aggressively. -|=========================================================== +It is strongly recommended to not use a ZFS volume for a swap partition because this could lead to deadlocks freezing thge affected system and other unpredictable behavior. The OpenZFS documentation, which can be viewed https://openzfs.github.io/openzfs-docs/Project%20and%20Community/FAQ.html#using-a-zvol-for-a-swap-device-on-linux[here], warns against using a ZFS volume for a swap partition. [[zfs_encryption]] Encrypted ZFS Datasets -- 2.39.5 _______________________________________________ pve-devel mailing list pve-devel@lists.proxmox.com https://lists.proxmox.com/cgi-bin/mailman/listinfo/pve-devel