From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from firstgate.proxmox.com (firstgate.proxmox.com [IPv6:2a01:7e0:0:424::9]) by lore.proxmox.com (Postfix) with ESMTPS id 05B661FF153 for ; Mon, 22 Jun 2026 10:51:47 +0200 (CEST) Received: from firstgate.proxmox.com (localhost [127.0.0.1]) by firstgate.proxmox.com (Proxmox) with ESMTP id 31F5533AF; Mon, 22 Jun 2026 10:51:45 +0200 (CEST) Mime-Version: 1.0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset=UTF-8 Date: Mon, 22 Jun 2026 10:51:09 +0200 Message-Id: To: "David Riley" , "Lukas Sichert" , Subject: Re: [PATCH manager v3] fix #4503: ui: qemu: add detect zeroes disk option From: "Daniel Kral" X-Mailer: aerc 0.21.0-145-gf21bb67f8cab-dirty References: <20260618115005.45266-1-l.sichert@proxmox.com> <7a2d0777-1fb4-4a87-99ed-2c77caa0082b@proxmox.com> In-Reply-To: <7a2d0777-1fb4-4a87-99ed-2c77caa0082b@proxmox.com> X-Bm-Milter-Handled: 55990f41-d878-4baa-be0a-ee34c49e34d2 X-Bm-Transport-Timestamp: 1782118260765 X-SPAM-LEVEL: Spam detection results: 0 AWL 0.074 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 Message-ID-Hash: 6TGQ6MUU25IUGQXRXQ6VRCW43JYCFYIC X-Message-ID-Hash: 6TGQ6MUU25IUGQXRXQ6VRCW43JYCFYIC X-MailFrom: d.kral@proxmox.com X-Mailman-Rule-Misses: dmarc-mitigation; no-senders; approved; loop; banned-address; emergency; member-moderation; nonmember-moderation; administrivia; implicit-dest; max-recipients; max-size; news-moderation; no-subject; digests; suspicious-header X-Mailman-Version: 3.3.10 Precedence: list List-Id: Proxmox VE development discussion List-Help: List-Owner: List-Post: List-Subscribe: List-Unsubscribe: On Fri Jun 19, 2026 at 1:01 PM CEST, David Riley wrote: > On 6/18/26 1:49 PM, Lukas Sichert wrote: >> When discard is enabled, qemu-server defaults to 'detect-zeroes=3Dunmap'= . >> This can have a significant performance impact for zero writes on some >> setups, while users might still want to keep guest discard/TRIM support >> enabled. >> >> Allow configuring the option independently so 'discard' can stay enabled >> while zero detection is disabled. Persist the checkbox state explicitly, >> as the backend treats an absent value as default-enabled behavior, >> resulting in 'detect-zeroes=3Dunmap' when 'discard' is enabled. > > Thanks for submitting this patch. > > While it clearly addresses the performance issues reported in #4503 > [0], I was reading through the Bugzilla thread and noticed a request > to support the third QEMU state for detect_zeroes [1]. Currently, the > underlying parameter supports off, on, and unmap [2]. > > Since we are already modifying this configuration in the UI, it might > make sense to fully expose all three options to the user rather than > just a binary toggle as there is a difference between "on" and > "unmap". This would need adapting the detect_zeroes option and parsing logic (it's only boolean right now) so it can take any of the 3 valid values by QEMU and be backwards compatible to the old values in our config. This should probably also check the constraint that detect-zeroes=3Dunmap can only be set if discard=3Dunmap, but the error message seems already be quite clear for that [0]. [0] https://gitlab.com/qemu-project/qemu/-/blob/master/block.c?ref_type=3Dh= eads#L1120 > > [0] https://bugzilla.proxmox.com/show_bug.cgi?id=3D4503 > [1] https://bugzilla.proxmox.com/show_bug.cgi?id=3D4503#c8 > [2] https://www.qemu.org/docs/master/interop/qemu-storage-daemon-qmp-ref.= html#enum-QSD-block-core.BlockdevDetectZeroesOptions > >> Link: https://bugzilla.proxmox.com/show_bug.cgi?id=3D4503 >> Signed-off-by: Lukas Sichert >> --- >> >> Notes: >> changes from v2 to v3 (thanks @Fabian): >> - add a comment explaining why this property is handled differently= from >> the others >> =20 >> changes from v1 to v2: >> - added bug-numer to commit header >> - appended bug-link to commit body >> >> www/manager6/qemu/HDEdit.js | 10 ++++++++++ >> 1 file changed, 10 insertions(+) >> >> [...] >>