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[openzfs.github.io] URIBL_SBL_A 0.1 Contains URL's A record listed in the Spamhaus SBL blocklist [185.199.108.153, 185.199.110.153, 185.199.111.153] Subject: [pve-devel] [PATCH pve-docs v3] fix #5644: Split the section on creating a swap partition on a ZVol. 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> The section "SWAP on ZFS" was split into two parts. The first part contains general instructions on how to create a swap partition and how to set the level of "swappiness". The second part contains a warning about creating a swap partition on a ZFS volume.The official ZFS documentation, which has been linked in a footnote, explains that creating a swap partition on a ZFS volume could lead to dangerous and undefined behavior. Signed-off-by: Alexander Abraham <a.abraham@proxmox.com> --- local-zfs.adoc | 26 +++++++++++++++----------- 1 file changed, 15 insertions(+), 11 deletions(-) diff --git a/local-zfs.adoc b/local-zfs.adoc index c64fb27..d411222 100644 --- a/local-zfs.adoc +++ b/local-zfs.adoc @@ -622,14 +622,9 @@ time this value changes: You *must reboot* to activate these changes. ==== - -[[zfs_swap]] -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. +[[creating_swap_partitions]] +Creating SWAP Partitions +~~~~~~~~~~~~~~~~~~~~~~~~ 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 @@ -637,18 +632,18 @@ 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"] |=========================================================== @@ -663,6 +658,15 @@ improve performance when sufficient memory exists in a system. | vm.swappiness = 100 | The kernel will swap aggressively. |=========================================================== +[[zfs_swap]] +SWAP on ZFS +~~~~~~~~~~~ + +It is strongly recommended to not use a ZFS volume for creating a swap partition +because this could lead to deadlocks. These deadlocks could cause the affected +system to freeze. The OpenZFS documentation footnote:[https://openzfs.github.io/openzfs-docs/Project%20and%20Community/FAQ.html#using-a-zvol-for-a-swap-device-on-linux] +warns about using a ZFS volume for creating 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