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 84C9D1FF168 for ; Tue, 4 Mar 2025 18:03:08 +0100 (CET) Received: from firstgate.proxmox.com (localhost [127.0.0.1]) by firstgate.proxmox.com (Proxmox) with ESMTP id 231456572; Tue, 4 Mar 2025 18:03:04 +0100 (CET) Message-ID: <586a4d99-13c1-4bcc-b9b0-2718735dc797@proxmox.com> Date: Tue, 4 Mar 2025 18:03:00 +0100 MIME-Version: 1.0 User-Agent: Mozilla Thunderbird To: Thomas Lamprecht , Proxmox Backup Server development discussion , =?UTF-8?Q?Fabian_Gr=C3=BCnbichler?= References: <20250219164847.757184-1-c.ebner@proxmox.com> <20250219164847.757184-3-c.ebner@proxmox.com> <1741005633.eo593uhjhw.astroid@yuna.none> <1151f4cb-36f2-4bb7-9e15-1d52850cc23a@proxmox.com> <7c0d6e54-1f71-4c05-b4f6-00779b8d2673@proxmox.com> Content-Language: en-US, de-DE From: Christian Ebner In-Reply-To: <7c0d6e54-1f71-4c05-b4f6-00779b8d2673@proxmox.com> X-SPAM-LEVEL: Spam detection results: 0 AWL 0.030 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 RCVD_IN_VALIDITY_CERTIFIED_BLOCKED 0.001 ADMINISTRATOR NOTICE: The query to Validity was blocked. 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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 2/2] pbs api types: add option to set GC chunk cleanup wait period X-BeenThere: pbs-devel@lists.proxmox.com X-Mailman-Version: 2.1.29 Precedence: list List-Id: Proxmox Backup Server development discussion List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Reply-To: Proxmox Backup Server development discussion Content-Transfer-Encoding: 7bit Content-Type: text/plain; charset="us-ascii"; Format="flowed" Errors-To: pbs-devel-bounces@lists.proxmox.com Sender: "pbs-devel" On 3/4/25 17:49, Thomas Lamprecht wrote: > Am 04.03.25 um 17:37 schrieb Christian Ebner: >> On 3/4/25 17:01, Thomas Lamprecht wrote: >>> Would be fine by me to reducing the minimum to zero. And the extra 5 >>> minutes are "just to be sure" safety-margin, not a requirement for >>> anything IIRC. >> >> Discussed this with Fabian rather extensively today. Only reason to keep >> a small safety margin here is for small time drift in case of remote >> storages (if they use their local time for timestamps). > > Ah, you mean network attached remote storage, but while your reasons > below are fine, doing this for time drifts is IMO not really strong > argumentation, as if one allows for no time synchronisation then there > won't be a limit to the drift amount, but ... > > >> But this can be much lower, would opt for 1 minute to stay within the >> minute range. >> >> Also, atime always uses the coarse resolution for timestamp updates, >> that will also not change with the multi-grained timestamp resolutions >> in https://origin.kernel.org/doc/html/v6.13/filesystems/multigrain-ts.html >> So this has to be taken into account for the atime update check, and >> since setting the atime into the past will introduce other error modes >> (permissions, fs impl, ...), a short wait of a 1 second in-between must >> be used. >> >> Also, there is no distinction to be made between filesystems mounted >> with atime and relatime, if the explicit atime update fails, the GC > > ... this actually is a strong argument, so I'm fine with a Minute as > minimum. >>> Maybe something with "cutoff", like just gc_cutoff or gc_atime_cutoff, >>> as a cut-off of which chunks we even consider for removal is basically >>> what this is. >> >> I would opt for gc-atime-safety-check and gc-atime-safety-margin, to >> show that they are related and their implicit function > > meh, do not find safety-check/margin very telling and safety is a bit too > generic and also slightly overused term IMO. What's wrong with cutoff? Nothing wrong with it, but Fabian pointed out that naming the opt-out flag for the check `gc-atime-check` is a bit to generic, as atimes are always checked by the GC, the better naming was `gc-atime-safety-check`, and therefore the `gc-atime-safety-margin` might make the correlation more clear, as it will only be allowed to set the latter, if the former is enabled. But I can of course go with the `gc-atime-cutoff`. >> Also, there will be no upper limit for the gc-atime-safety-margin, as >> Fabian pointed out correctly, setting this to large values might be >> desired to avoid data loss if something is off, and one notices from >> e.g. the pending removals. > > I'm rather a fan of _some_ limits even if only to be proven wrong by user > demand to go over that, but then we actually know the use case. As until > now we got no request at all for this to be higher, IIRC, I'd go for two > days. > > Data loss is prevented by additional copies on other servers and mediums > (keyword: tape or soon s3) Yes, agreed! Although still a lot of work ahead for the latter one... _______________________________________________ pbs-devel mailing list pbs-devel@lists.proxmox.com https://lists.proxmox.com/cgi-bin/mailman/listinfo/pbs-devel