From nobody Sat Dec 16 20:25:11 2023 X-Original-To: freebsd-net@mlmmj.nyi.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2610:1c1:1:606c::19:1]) by mlmmj.nyi.freebsd.org (Postfix) with ESMTP id 4SsyJY6XYXz52g22; Sat, 16 Dec 2023 20:25:33 +0000 (UTC) (envelope-from hausen@punkt.de) Received: from mail.punkt.de (mail.punkt.de [IPv6:2a00:b580:8000:11:1c6b:7032:35e9:5616]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client did not present a certificate) by mx1.freebsd.org (Postfix) with ESMTPS id 4SsyJX5YPlz4Pfy; Sat, 16 Dec 2023 20:25:32 +0000 (UTC) (envelope-from hausen@punkt.de) Authentication-Results: mx1.freebsd.org; dkim=none; spf=pass (mx1.freebsd.org: domain of hausen@punkt.de designates 2a00:b580:8000:11:1c6b:7032:35e9:5616 as permitted sender) smtp.mailfrom=hausen@punkt.de; dmarc=none Received: from smtpclient.apple (unknown [IPv6:2003:a:d59:3800:cd57:70fe:6ed:e47a]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.punkt.de (Postfix) with ESMTPSA id B1C7D6D39E; Sat, 16 Dec 2023 21:25:22 +0100 (CET) From: "Patrick M. Hausen" Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable List-Id: Networking and TCP/IP with FreeBSD List-Archive: https://lists.freebsd.org/archives/freebsd-net List-Help: List-Post: List-Subscribe: List-Unsubscribe: Sender: owner-freebsd-net@freebsd.org Mime-Version: 1.0 (Mac OS X Mail 16.0 \(3774.200.91.1.1\)) Subject: Odd values for various memory metrics via SNMP Message-Id: <1EDAF2AC-3A2B-43BE-B66B-E095F5A80C2C@punkt.de> Date: Sat, 16 Dec 2023 21:25:11 +0100 To: FreeBSD-STABLE Mailing List , FreeBSD Net X-Mailer: Apple Mail (2.3774.200.91.1.1) X-Spamd-Result: default: False [-1.26 / 15.00]; NEURAL_HAM_MEDIUM(-1.00)[-1.000]; NEURAL_HAM_LONG(-0.99)[-0.990]; NEURAL_SPAM_SHORT(0.53)[0.532]; MV_CASE(0.50)[]; R_SPF_ALLOW(-0.20)[+ip6:2a00:b580::/32]; MIME_GOOD(-0.10)[text/plain]; RCVD_COUNT_ONE(0.00)[1]; MLMMJ_DEST(0.00)[freebsd-net@freebsd.org,freebsd-stable@freebsd.org]; R_DKIM_NA(0.00)[]; ASN(0.00)[asn:16188, ipnet:2a00:b580::/32, country:DE]; MIME_TRACE(0.00)[0:+]; FROM_EQ_ENVFROM(0.00)[]; RCPT_COUNT_TWO(0.00)[2]; RCVD_VIA_SMTP_AUTH(0.00)[]; RCVD_TLS_ALL(0.00)[]; ARC_NA(0.00)[]; TO_DN_ALL(0.00)[]; FROM_HAS_DN(0.00)[]; DMARC_NA(0.00)[punkt.de]; TO_MATCH_ENVRCPT_ALL(0.00)[]; MID_RHS_MATCH_FROM(0.00)[] X-Rspamd-Queue-Id: 4SsyJX5YPlz4Pfy X-Spamd-Bar: - Hi all, what's the best platform/list/forum/... to discuss issues with the SNMP = implementations for FreeBSD? Since I started to dig deeper into Obervium I found that of = all the systems I own only the FreeBSD based ones present some challenges regarding the = interpretation of memory metrics. 1. I confirmed that this is not an Observium artefact. LibreNMS and = manual snmpwalk give the same results. 2. This is independent of the question if you use net-snmp (FreeNAS, = OPNsense) or bsnmpd in base (my Raspberry Pi cluster). 3. These are the systems concerned: - OPNsense - FreeBSD 13.2, AMD64, 8 G of RAM, net-snmp - FreeNAS - TrueANS CORE, FreeBSD 13.1, AMD64, 64 G of RAM, net-snmp - 7 Raspberry Pi CM 3+, AARCH64, 1 G of RAM, bsnmpd 4. The "odd" metrics: - "Real Memory" OPNsense: 762 of 768 M (yes!) used, flagged "red" in Observium, of = course FreeNAS: 35.9 of 36.1 G used All the Pis: 178 of 179 M used All - see hardware description above - no connection to the "real real" = memory installed. For comparison: ESXi 8.0: 26.7 of 31.9 G used - the system has got 32 G = of RAM installed. - "Shared real memory" OPNsense: 97.1 of 103 M used FreeNAS: 593 of 774 M used Pis: 11.8 of 12.4 M used - Shared virtual memory Only systems running net-snmp have this, bsnmpd based ones don't. OPNsense: 166 of 233 M used FreeNAS: 1028.27 M of 1.49 G used - Virtual Memory Again, only via net-snmp. OPNsense: 5.03 of 5.11 G used FreeNAS: 628 of 628 G used - that's particularly weird for a system with = 64 G of RAM installed and not swapping or anything. For comparison: my only Linux based system: 12.7 of 29.6 G used - the = system has 16 G of RAM plus 16 G of swap, that seems to match the "29.6". For me these numbers don't make any sense at all. The motivation to = write this email: I am planning to use SNMP based monitoring, probably Observium, for all = our data centres, which means > 100 FreeBSD based hosts. The point of a = monitoring/management system is that anything flagged "red" is a real problem that needs = attention and the default state should be "everything super green". Things flagged "red" but = "everybody knows it can be ignored" bind a huge amount of brain capacity on behalf of the = operators. Not good. So what is going on here? What do these numbers actually mean? Where do = they come from? Are they artefacts of the SNMP implementation not taylored = perfectly for FreeBSD or are they some real metric that ends up interpreted wrong in the NMS = (Observium)? Thanks and kind regards, Patrick --=20 punkt.de GmbH Patrick M. Hausen .infrastructure Sophienstr. 187 76185 Karlsruhe Tel. +49 721 9109500 https://infrastructure.punkt.de info@punkt.de AG Mannheim 108285 Gesch=C3=A4ftsf=C3=BChrer: Daniel Lienert, Fabian Stein