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 00FD61FF15E for <inbox@lore.proxmox.com>; Tue, 8 Apr 2025 17:07:27 +0200 (CEST) Received: from firstgate.proxmox.com (localhost [127.0.0.1]) by firstgate.proxmox.com (Proxmox) with ESMTP id 99EDC31679; Tue, 8 Apr 2025 17:07:23 +0200 (CEST) From: Fiona Ebner <f.ebner@proxmox.com> To: pve-devel@lists.proxmox.com Date: Tue, 8 Apr 2025 17:07:15 +0200 Message-Id: <20250408150715.105253-4-f.ebner@proxmox.com> X-Mailer: git-send-email 2.39.5 In-Reply-To: <20250408150715.105253-1-f.ebner@proxmox.com> References: <20250408150715.105253-1-f.ebner@proxmox.com> MIME-Version: 1.0 X-SPAM-LEVEL: Spam detection results: 0 AWL -0.037 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 KAM_SHORT 0.001 Use of a URL Shortener for very short URL SPF_HELO_NONE 0.001 SPF: HELO does not publish an SPF Record SPF_PASS -0.001 SPF: sender matches SPF record Subject: [pve-devel] [PATCH docs 3/3] qm: virtiofs: drop writeback cache 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> 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> VirtIO-fs using writeback cache seems very broken at the moment. If a guest accesses a file (even just using 'touch'), that the host is currently writing, the guest can permanently end up with a truncated version of that file. Even subsequent operations like moving the file, will not result in the correct file being visible, but just rename the truncated one. Signed-off-by: Fiona Ebner <f.ebner@proxmox.com> --- qm.adoc | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/qm.adoc b/qm.adoc index 539912a..1babb82 100644 --- a/qm.adoc +++ b/qm.adoc @@ -1309,7 +1309,7 @@ has been configured in the resource mapping. Additionally, you can set the `cache` option to either `always`, `never`, `metadata`, or `auto` (default: `auto`), depending on your requirements. How the different caching modes behave can be read https://lwn.net/Articles/774495/[here under the "Caching Modes" -section]. To enable writeback cache set `writeback` to `1`. +section]. Virtiofsd supports ACL and xattr passthrough (can be enabled with the `expose-acl` and `expose-xattr` options), allowing the guest to access ACLs and @@ -1327,7 +1327,7 @@ applications do their own caching. ---- qm set <vmid> -virtiofs0 dirid=<dirid>,cache=always,direct-io=1 qm set <vmid> -virtiofs1 <dirid>,cache=never,expose-xattr=1 -qm set <vmid> -virtiofs2 <dirid>,expose-acl=1,writeback=1 +qm set <vmid> -virtiofs2 <dirid>,expose-acl=1 ---- To temporarily mount virtio-fs in a guest VM with the Linux kernel virtio-fs -- 2.39.5 _______________________________________________ pve-devel mailing list pve-devel@lists.proxmox.com https://lists.proxmox.com/cgi-bin/mailman/listinfo/pve-devel