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 367C968FC8 for ; Wed, 10 Mar 2021 09:24:23 +0100 (CET) Received: from firstgate.proxmox.com (localhost [127.0.0.1]) by firstgate.proxmox.com (Proxmox) with ESMTP id 257AA1A0B4 for ; Wed, 10 Mar 2021 09:23:53 +0100 (CET) Received: from mout.web.de (mout.web.de [217.72.192.78]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange ECDHE (P-256) server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by firstgate.proxmox.com (Proxmox) with ESMTPS id 95E041A0AA for ; Wed, 10 Mar 2021 09:23:52 +0100 (CET) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=web.de; s=dbaedf251592; t=1615364632; bh=AhfD45gsdDb9G9eR0HnG6MbFHBL+KsgiulWF1iIFwbI=; h=X-UI-Sender-Class:Subject:To:References:From:Date:In-Reply-To; b=cht7b9fZ+ggjAuKKYmnuOMQtHQQQBCxUyafmkAfOAGKaIcPWpXs5YGjRxc5wCcvDg vpF2+N0BK8qrmVEpXroku/Pm9btG0Lymf8aAsQcmgOEWLNTscQ/fcDCQp2hbY0/uW7 71aqnMVJH6UTBEyxyUPye48xX0xHZ61h9yJOp6/g= X-UI-Sender-Class: c548c8c5-30a9-4db5-a2e7-cb6cb037b8f9 Received: from Rolands-MacBook-Pro.cybercon.de ([87.79.213.20]) by smtp.web.de (mrweb103 [213.165.67.124]) with ESMTPSA (Nemesis) id 0MK20H-1lLHcy0SZR-001Qiz; Wed, 10 Mar 2021 09:18:33 +0100 To: Thomas Lamprecht , Proxmox VE development discussion References: <792c380c-6757-e058-55f6-f7d5436417f9@web.de> <3463e859-a6d9-ea66-481e-4f7548306e7d@proxmox.com> From: Roland Message-ID: <39c0fe3b-8261-8477-e501-f728bcb4c051@web.de> Date: Wed, 10 Mar 2021 09:18:36 +0100 User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.13; rv:78.0) Gecko/20100101 Thunderbird/78.8.0 MIME-Version: 1.0 In-Reply-To: <3463e859-a6d9-ea66-481e-4f7548306e7d@proxmox.com> Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: quoted-printable X-Provags-ID: V03:K1:quxV5fZxk3bxScsQMhOFGBZgHUj9VAs61DWcez2EWngqoXzCy72 KeL+meQ1c9yQA0nCYiGi9ktP1Qyb/iq3Ef+/FYqfrGuSoVTAoEuhX10WXqmLrUm1Ddyv7O/ OT0V6FUf/SCkxAeS5SqDIoGYRczlIx36JRblmTbelN+oqrrr4GbrjXTdfbZGQhoDYNQ9k9w oV/8j1wTirbH7z9RhrqQg== X-Spam-Flag: NO X-UI-Out-Filterresults: notjunk:1;V03:K0:U3mtADKrmc4=:fiESz8gpMftHVnmmBCyT// Tq+1xsm7z9P/MHEXJAQrEuYsF3VQ3CF0Qjelpp4+lHIIVWzH8Nkh8hyDHi24RBgV12OE+2IOG JUY1ptBqVMC6YDtWRYiqnhcJsBcAhGHBbTKBAw6v3RQeXLooxD8beRhOp2TJ7cqL7sPqA1xTq UzJNrwFhYYiXrpXqC1DqtjA1lV2dYvF+RETSTI6wsPO+o0DlXpHhHwrqY0dSHmjQath6OKEYD 1TtraurxqSEcVItXZv0i8OP1PhNLjeVeM99/1kQDl8w4NVKurqnsghmkcunPHFzXyQHN9fp1v VgqxDn0WrzUaeDWxc1De7L/6535oPrrMGVEi7WVztWJW/GTFpT7oLJ2CKnV4XtVuGjU63Bzk4 YaMD0gP48lSRLECvH8gqDniUJ55WUvhDY83Z9Cwsfk0fmffDjxzunhBIffsqRdxnpy3ckuylh SIg3E7rSOJwnaz/dcC2oF33e1xsa85NaUa6HxbTKVcZVc2LVevDHBuApUQwlzDWhLU67B+lxo /Ph8sMfjBlqaUE/RmkiaJVehQwZCMULJTe5ub1mvJV/7N2JTdWz5RRvYGKvP6TXyB+OWD1DNc Y0GeQUCGhYyEyOggeEa0Hkjc20SK5dPaFQKzAtf3r0tM/xxvu0DdpbGM4lyY/ASIS2kBK+jsv p8DQQMk0UbEaOWdqsFK0JGZWj2pLvqAqp70h4zOqVYP4wPnVwQ1PUNQGGvXU5qXHD7YDv/RxA e2IIeGY/lot55frlDiLR7ZMYP2Ohnxavz0ItDDUp2BhgSaA99dUvMyyL2mz9ZRh/pIG5GPwhZ bU//pLukV3CunmxoGBRvBymiCqfBbbyFZKExjQlogjS07/EoSSsR8x9d3YUEvOYZl4kC50yQj uBkOM0HayHuqlQsjCixg== X-SPAM-LEVEL: Spam detection results: 0 AWL -0.738 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 FREEMAIL_FROM 0.001 Sender email is commonly abused enduser mail provider NICE_REPLY_A -0.001 Looks like a legit reply (A) RCVD_IN_DNSWL_LOW -0.7 Sender listed at https://www.dnswl.org/, low trust RCVD_IN_MSPIKE_H2 -0.001 Average reputation (+2) SPF_HELO_NONE 0.001 SPF: HELO does not publish an SPF Record SPF_PASS -0.001 SPF: sender matches SPF record Subject: Re: [pve-devel] avoidable writes of pmxcfs to /var/lib/pve-cluster/config.db ? X-BeenThere: pve-devel@lists.proxmox.com X-Mailman-Version: 2.1.29 Precedence: list List-Id: Proxmox VE development discussion List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 10 Mar 2021 08:24:23 -0000 >> corruption in particular problem situations like server crash or whatev= er. > So the prime candidate for this write load are the PVE HA Local Resource > Manager services on each node, they update their status and that is ofte= n > required to signal the current Cluster Resource Manager's master service > that the HA stack on that node is well alive and that commands got > executed with result X. So yes, this is required and intentional. > There maybe some room for optimization, but its not that straight forwar= d, > and (over-)clever solutions are often the wrong ones for an HA stack - a= s > failure here is something we really want to avoid. But yeah, some easier > to pick fruits could maybe be found here. > > The other thing I just noticed when checking out: > # ls -l "/proc/$(pidof pmxcfs)/fd" > > to get the FDs for all db related FDs and then watch writes with: > # strace -v -s $[1<<16] -f -p "$(pidof pmxcfs)" -e write=3D4,5,6 > > Was seeing additionally some writes for the RSA key files which should j= ust > not be there, but I need to closer investigate this, seemed a bit too od= d > to > me. not only these, i also see constant rewrite of=C2=A0 (non-changing?) vm configuration data , too. just cat config.db-wal |strings|grep ..... |sort | uniq -c=C2=A0=C2=A0 to = see what's getting there. the weird thing is, that it does not happen for every VM. just some. i send you an email with additional data (don't want to post all my VMs mac adresses in public) > > I'll see if I can find out a bit more details about above, maybe there's > something to improve lurking there. > > FWIW, in general we try to keep stuff rather simple, the main reason is = that > simpler systems tend to work more reliable and are easier to maintain, a= nd > the load of even simple services can still get quite complex in sum, lik= e > in > PVE; But we still try to avoid efficiency trade offs over oversimplifica= tion. thanks for explaining , for the hints how to trace writes and for having a look. sure, critical components SHOULD be simple! roland