From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: 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)) (No client certificate requested) by lists.proxmox.com (Postfix) with ESMTPS id 0790C69430 for ; Mon, 26 Jul 2021 10:54:42 +0200 (CEST) Received: from firstgate.proxmox.com (localhost [127.0.0.1]) by firstgate.proxmox.com (Proxmox) with ESMTP id E727EA506 for ; Mon, 26 Jul 2021 10:54:11 +0200 (CEST) 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)) (No client certificate requested) by firstgate.proxmox.com (Proxmox) with ESMTPS id 6E15BA4F9 for ; Mon, 26 Jul 2021 10:54:11 +0200 (CEST) Received: from proxmox-new.maurer-it.com (localhost.localdomain [127.0.0.1]) by proxmox-new.maurer-it.com (Proxmox) with ESMTP id 3CEDA4278B for ; Mon, 26 Jul 2021 10:54:11 +0200 (CEST) To: Dietmar Maurer , Proxmox Backup Server development discussion References: <1781641437.1181.1627289020670@webmail.proxmox.com> From: Dominik Csapak Message-ID: <132e7fa3-018b-4492-c1ab-2ffc136ad965@proxmox.com> Date: Mon, 26 Jul 2021 10:54:10 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Thunderbird/78.12.0 MIME-Version: 1.0 In-Reply-To: <1781641437.1181.1627289020670@webmail.proxmox.com> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit X-SPAM-LEVEL: Spam detection results: 0 AWL 1.054 Adjusted score from AWL reputation of From: address BAYES_00 -1.9 Bayes spam probability is 0 to 1% KAM_DMARC_STATUS 0.01 Test Rule for DKIM or SPF Failure with Strict Alignment NICE_REPLY_A -1.091 Looks like a legit reply (A) 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-backup v2 0/7] improve catalog handling 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: , X-List-Received-Date: Mon, 26 Jul 2021 08:54:42 -0000 On 7/26/21 10:43 AM, Dietmar Maurer wrote: > >> On 07/26/2021 10:37 AM Dominik Csapak wrote: >> >> >> On 7/26/21 10:26 AM, Dietmar Maurer wrote: >>> >>>> On 07/22/2021 3:40 PM Dominik Csapak wrote: >>>> >>>> this series combines my previous catalog related patch-series[0][1][2] >>>> >>>> changes the catalog interface to be more concise, optimizes catalog >>>> commit calls during restore, and implements a fast catalog for the >>>> gui which only contains the snapshot lists >>>> >>>> changes from v1: >>>> * only write snapshot list in new 'finish' method of the catalog >>>> * add 'finish' also to pool writer >>>> * replace pending offset counter with reducing the chunk_archive >>>> interface of the catalog >>> >>> Now, during tape backup, users do not see any progress on the GUI. This >>> can be particularly confusing on long running tape backups. >>> >>> A simpler approach would be to only generate cache files for "finished" tapes (content >>> will never change), while using the original catalog for tapes still writable. This should >>> be much easier to implement? >>> >> >> yes it would be simpler, but this does not completely solve the issue of >> slow reads on large slow catalogs? (the last tape of the media-set can >> still be so big that the reads take too long?) > > I thought the performance problem is on media-sets with many tapes. > A single catalog should not cause a large delay? > many tapes makes the problem worse/more likely, but in general if my disk is too slow to read a catalog in reasonable time, the ux suffers. AFAIU a single catalog can be larger than 250MiB, which, when on a storage that is slow to begin with and maybe under load, can take quite some time to read completely. e.g. 300MiB / 10MiB/s (slow spinner + big load) = 30s not great ux when i have to wait more than half a minute to show the content of my tape backup in contrast, having a tape with 100000 snapshots with a 'fast catalog' 100000 * 50 bytes ~ 5 MiB should load in under a second