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 1B65665B38 for ; Fri, 24 Jul 2020 09:03:10 +0200 (CEST) Received: from firstgate.proxmox.com (localhost [127.0.0.1]) by firstgate.proxmox.com (Proxmox) with ESMTP id 06A4C2EF89 for ; Fri, 24 Jul 2020 09:02:40 +0200 (CEST) Received: from pmg.fws.fr (pmg.fws.fr [51.91.175.36]) (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 id 265F62EF7E for ; Fri, 24 Jul 2020 09:02:39 +0200 (CEST) Received: from pmg.fws.fr (localhost [127.0.0.1]) by pmg.fws.fr (Proxmox) with ESMTP id 97A85C1A8E; Fri, 24 Jul 2020 09:02:32 +0200 (CEST) Received: from zmproxy.fws.fr (zmproxy.fws.fr [10.29.1.17]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by pmg.fws.fr (Proxmox) with ESMTPS id 70938C061C; Fri, 24 Jul 2020 09:02:31 +0200 (CEST) Received: from zmproxy.fws.fr (localhost [127.0.0.1]) by zmproxy.fws.fr (Postfix) with ESMTPS id 615628CEF0D; Fri, 24 Jul 2020 09:02:31 +0200 (CEST) Received: from zmproxy.fws.fr (localhost [127.0.0.1]) by zmproxy.fws.fr (Postfix) with ESMTPS id 3B4798CEF0E; Fri, 24 Jul 2020 09:02:31 +0200 (CEST) DKIM-Filter: OpenDKIM Filter v2.10.3 zmproxy.fws.fr 3B4798CEF0E DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=firewall-services.com; s=7DAD15A2-D84A-11E9-8F77-BEC4FAA34EBC; t=1595574151; bh=4EhW96UKTFsjUT8q5qLzz4+UdHTLquDbnLaoeXpcM6E=; h=Date:From:To:Message-ID:MIME-Version; b=Ho7PxT8+XPInS2N6EH6Dk7GXb3+WCzqPccTjJpHLDqXx7nVPkunK3sXo1K1XV32E/ 6sZyGQ4A4ipYN21MYDT6aiCsCxFv0p2rEvkvIEKDGNpnSxih/m40m2DMaZL074C6qJ 3DO8lZoVtLAjng4o9QZdgEBp+fG97eP5t9FOk6QKQEF+xn0F/xnPIc0jc8p13H5SmW 9OqKKRpdbgnUOKe+oI/cW1qpm7Tf/iM1FGrXKaAMKFjecuUIAqLfzhh2rYY4sLWXNv HI6sm5wajsl1JwRcM9dgfd3V06BSGxqqfy2kGy47ZyLRQtkCtiobw7vwju940x2VPl UGAM/KBU4914g== Received: from zmstore.fws.fr (zmstore.fws.fr [10.29.3.15]) by zmproxy.fws.fr (Postfix) with ESMTP id 216BA8B3580; Fri, 24 Jul 2020 09:02:31 +0200 (CEST) Date: Fri, 24 Jul 2020 09:02:30 +0200 (CEST) From: Daniel Berteaud To: Roland Cc: Proxmox VE user list Message-ID: <945247964.82475.1595574150577.JavaMail.zimbra@fws.fr> In-Reply-To: References: <1110267368.76036.1595436034847.JavaMail.zimbra@fws.fr> <1595486387.pi9zv7y79a.astroid@nora.none> <141180690.77175.1595487181182.JavaMail.zimbra@fws.fr> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable X-Originating-IP: [10.29.1.17] X-Mailer: Zimbra 8.8.15_GA_3955 (ZimbraWebClient - GC83 (Linux)/8.8.15_GA_3953) Thread-Topic: PBS : is dirty-bitmap really accurate ? Thread-Index: 6SMqAdDaXM2sFDFfuu4k7mC49W4eUw== X-SPAM-LEVEL: Spam detection results: 0 AWL 0.028 Adjusted score from AWL reputation of From: address DKIM_SIGNED 0.1 Message has a DKIM or DK signature, not necessarily valid DKIM_VALID -0.1 Message has at least one valid DKIM or DK signature DKIM_VALID_AU -0.1 Message has a valid DKIM or DK signature from author's domain DKIM_VALID_EF -0.1 Message has a valid DKIM or DK signature from envelope-from domain RCVD_IN_DNSWL_MED -2.3 Sender listed at https://www.dnswl.org/, medium trust 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. [firewall-services.com, fws.fr] Subject: Re: [PVE-User] PBS : is dirty-bitmap really accurate ? 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: Fri, 24 Jul 2020 07:03:10 -0000 ----- Le 23 Juil 20, =C3=A0 23:59, Roland devzero@web.de a =C3=A9crit : > i just had a look on that, too - i was backing up a VM i backed up this > afternoon, >=20 > and for my curiosity 1GB out of 15GB was marked dirty. >=20 > that looks a quite much for me for a mostly idle system, because there > was definitely only a little bit of change on the system within logfiles > in /var/log >=20 > so i wonder what marked all that blocks dirty.... >=20 > i'm also suspecting atime changes...will keep an eye on that.... It was my daily fstrim in my case. Each time you trim, it'll dirty all the = blocks corresponding to unused space. I've switched this to a weekly job so bacups can run most of the time effic= iently. Since then, dirty blocks went from ~15GB per VM on average to somet= hing betwwen 800MB and 4GB, which is much closer to what I expect, consider= ing the 4MB granularity of the bitmap. I'll check on my biggest VM (Zabbix server) but I expect similar results Thanks Fabian and Jorge for pointing this out Cheers Daniel --=20 [ https://www.firewall-services.com/ ] =09 Daniel Berteaud=20 FIREWALL-SERVICES SAS, La s=C3=A9curit=C3=A9 des r=C3=A9seaux=20 Soci=C3=A9t=C3=A9 de Services en Logiciels Libres=20 T=C3=A9l : +33.5 56 64 15 32=20 Matrix: @dani:fws.fr=20 [ https://www.firewall-services.com/ | https://www.firewall-services.com ]