From owner-freebsd-questions@freebsd.org Wed Mar 29 05:06:57 2017 Return-Path: Delivered-To: freebsd-questions@mailman.ysv.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:1900:2254:206a::19:1]) by mailman.ysv.freebsd.org (Postfix) with ESMTP id 9CCC7D236CC for ; Wed, 29 Mar 2017 05:06:57 +0000 (UTC) (envelope-from web@3dresearch.com) Received: from smtpd.telissant.net (smtpd.telissant.net [104.225.1.170]) (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 7ABCB3861 for ; Wed, 29 Mar 2017 05:06:56 +0000 (UTC) (envelope-from web@3dresearch.com) Received: from elettra.3dresearch.com (unknown [71.112.245.98]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) (Authenticated sender: elettra) by smtpd.telissant.net (Postfix) with ESMTPSA id 046AA112984 for ; Wed, 29 Mar 2017 01:06:55 -0400 (EDT) Received: from elettra.3dresearch.com (localhost [127.0.0.1]) by elettra.3dresearch.com (Postfix) with SMTP id 62131BFDAC for ; Wed, 29 Mar 2017 01:06:54 -0400 (EDT) Date: Wed, 29 Mar 2017 01:06:46 -0400 From: Janos Dohanics To: FreeBSD Questions Subject: Re: Unresponsive system Message-Id: <20170329010646.80416142d5c461af3a72842a@3dresearch.com> In-Reply-To: <20170329044528.63cec581.freebsd@edvax.de> References: <20170328160634.611573c82e88e1ca12d25891@3dresearch.com> <20170329044528.63cec581.freebsd@edvax.de> X-Mailer: Sylpheed 3.5.1 (GTK+ 2.24.29; amd64-portbld-freebsd10.3) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit X-BeenThere: freebsd-questions@freebsd.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: User questions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 29 Mar 2017 05:06:57 -0000 On Wed, 29 Mar 2017 04:45:28 +0200 Polytropon wrote: > On Tue, 28 Mar 2017 16:06:34 -0400, Janos Dohanics wrote: > > The system is FreeBSD 11.0-STABLE #0 r314885 amd64. It is mostly > > used to run Cyrus, Postfix, Amavisd, Clamd. Kernel is not > > customized, except for "ident". > > > > Could this problem be related to the additional swap space provided > > by a swapfile? > > > > # cat /etc/fstab > > # Device Mountpoint FStype Options > > # Dump Pass# > > /dev/ada0p2 none swap sw > > 0 0 /dev/ada0p3 / ufs rw > > 1 1 /dev/ada0p4 none swap > > sw 0 0 md0 none > > swap sw,file=/swapfile,late 0 0 > > > > # swapinfo -hm > > Device 1M-blocks Used Avail Capacity > > /dev/ada0p2 256 241M 15M 94% > > /dev/ada0p4 750 290M 460M 39% > > /dev/md0 4096 289M 3.7G 7% > > Total 5102 820M 4.2G 16% > > > > I'd appreciate your advice. > > Do you have statistics about your CPU and I/O load? Both can > cause a system to become unresponsive. Using swap will start > in case the RAM is "full", and because you have three mechanisms > of swap on the same disk (ada0), this could be the reason: You > have two swap partitions and a swap file, all of them residing > on the same disk, and all of them are in use, so that could be > the reason for I/O load... Hello Polytropon, I have no statistics beyond what I have in the logs (maillog, amavisd.log, messages), plus I have tried to keep an eye on top(1). I did notice that at times CPU utilization, RAM and swap use (before adding the 4 GB md(4) device as the attempted remedy) were close to 100%, while mailq(1) kept growing. You are quite right, I should have thought about I/O load, and I didn't. I'll do some experimentation. In the meantime, Google turned up this page which looks relevant to the error message in my original post: http://www.leidinger.net/freebsd/dox/kern/html/df/d20/uipc__socket_8c_source.html Could you please explain? -- Janos Dohanics