From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: <f.ebner@proxmox.com> Received: from firstgate.proxmox.com (firstgate.proxmox.com [212.224.123.68]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by lists.proxmox.com (Postfix) with ESMTPS id D539090FB4 for <pve-devel@lists.proxmox.com>; Fri, 26 Jan 2024 09:40:05 +0100 (CET) Received: from firstgate.proxmox.com (localhost [127.0.0.1]) by firstgate.proxmox.com (Proxmox) with ESMTP id BA77A324FB for <pve-devel@lists.proxmox.com>; Fri, 26 Jan 2024 09:39:35 +0100 (CET) Received: from proxmox-new.maurer-it.com (proxmox-new.maurer-it.com [94.136.29.106]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by firstgate.proxmox.com (Proxmox) with ESMTPS for <pve-devel@lists.proxmox.com>; Fri, 26 Jan 2024 09:39:34 +0100 (CET) Received: from proxmox-new.maurer-it.com (localhost.localdomain [127.0.0.1]) by proxmox-new.maurer-it.com (Proxmox) with ESMTP id 7819A4691F; Fri, 26 Jan 2024 09:39:34 +0100 (CET) Message-ID: <b750d1a4-0eaa-4edc-820b-ade6913360b2@proxmox.com> Date: Fri, 26 Jan 2024 09:39:30 +0100 MIME-Version: 1.0 User-Agent: Mozilla Thunderbird To: Dietmar Maurer <dietmar@proxmox.com>, Proxmox VE development discussion <pve-devel@lists.proxmox.com>, "DERUMIER, Alexandre" <alexandre.derumier@groupe-cyllene.com> References: <20240125144149.216064-1-f.ebner@proxmox.com> <20240125144149.216064-14-f.ebner@proxmox.com> <1540909020.1148.1706199226999@webmail.proxmox.com> <d61185422c0949e17e6929592342c211fe856815.camel@groupe-cyllene.com> <143499946.1270.1706206703161@webmail.proxmox.com> Content-Language: en-US From: Fiona Ebner <f.ebner@proxmox.com> In-Reply-To: <143499946.1270.1706206703161@webmail.proxmox.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit 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 T_SCC_BODY_TEXT_LINE -0.01 - Subject: Re: [pve-devel] [RFC docs 13/13] vzdump: add section about backup fleecing 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> X-List-Received-Date: Fri, 26 Jan 2024 08:40:05 -0000 Am 25.01.24 um 19:18 schrieb Dietmar Maurer: >>>> Stupid question: Wouldn't It be much easier to add a simple IO-buffer >>>> with limited capacity, implemented inside the RUST backup code? >> >> At work, we are running a backup cluster on remote location with hdd , >> and a production cluster with super fast nvme, >> and sometimes I have really big write spikes (in GB/s), so it's >> impossible for the backup storage or network to handle it without >> increase latency or saturate link. >> >> So with limited capacity (how much ? in memory ?), I don't think it >> solve the problem. If the buffer is full, the vm write will hang. > > Ok, I can see the problem... Yes, exactly. Sure, it could be done with an in-memory buffer. And while it would help some people, it would help in much fewer scenarios compared to fleecing, because RAM is almost always more expensive/more limited than storage space.