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 51A3169552 for ; Tue, 2 Mar 2021 11:23:33 +0100 (CET) Received: from firstgate.proxmox.com (localhost [127.0.0.1]) by firstgate.proxmox.com (Proxmox) with ESMTP id 3AD902AC17 for ; Tue, 2 Mar 2021 11:23:03 +0100 (CET) Received: from mail.merit.unu.edu (webmail.merit.unu.edu [192.87.143.6]) by firstgate.proxmox.com (Proxmox) with ESMTP id 686AE2AC09 for ; Tue, 2 Mar 2021 11:23:02 +0100 (CET) Received: from [192.87.143.100] (ws100.merit.unu.edu [192.87.143.100]) by mail.merit.unu.edu (Postfix) with ESMTPSA id 08A6880742B4A for ; Tue, 2 Mar 2021 11:22:55 +0100 (CET) To: Proxmox VE user list From: mj Message-ID: <82a59e22-1a52-e104-1217-ac904d9223ca@merit.unu.edu> Date: Tue, 2 Mar 2021 11:22:55 +0100 User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:78.0) Gecko/20100101 Thunderbird/78.8.0 MIME-Version: 1.0 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 -0.117 Adjusted score from AWL reputation of From: address 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 URIBL_BLOCKED 0.001 ADMINISTRATOR NOTICE: The query to URIBL was blocked. See http://wiki.apache.org/spamassassin/DnsBlocklists#dnsbl-block for more information. [readthedocs.io] Subject: [PVE-User] pbs incremental backups X-BeenThere: pve-user@lists.proxmox.com X-Mailman-Version: 2.1.29 Precedence: list List-Id: Proxmox VE user list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 02 Mar 2021 10:23:33 -0000 Hi, Testing PBS backups taken from PVE VMs on ceph rbd now. Very nice, very quick, very cool. :-) We have a question. Something we wonder about. In our current backup software, we make weekly full_system backups, and daily incremental_system backups, each incremental based on the same full_system backup. So: each daily incremental backup becomes bigger, until the weekend. Then we make a new full_system backup to base the next set of incrementals on. In PBS I cannot specify if a backup is full or incremental, we assume this means that automatically the first backup is a full_system backup, and subsequent backups are incremental. The PBS backup logs confirm this assumption, saying: "scsi0: dirty-bitmap status: created new" vs "scsi0: dirty-bitmap status: OK (7.3 GiB of 501.0 GiB dirty)" And now the question: At what point in time is a new full_system backup created, to rebase incremental backups on? Or is each incremental backup based on the previous incremental? And if that is the case, how will we ever be able to delete one of the in-between incrementals, because that would then break to whole chain of incremental_backup-based-on-incremental_backup...? We have read the page https://qemu.readthedocs.io/en/latest/interop/bitmaps.html but it does not seem to answer this. Anyone care to share some insight on this logic and how PBS works? MJ