From owner-freebsd-questions@FreeBSD.ORG Tue Oct 28 19:09:03 2014 Return-Path: Delivered-To: freebsd-questions@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:1900:2254:206a::19:1]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by hub.freebsd.org (Postfix) with ESMTPS id 53D3D1FE for ; Tue, 28 Oct 2014 19:09:03 +0000 (UTC) Received: from mail-wi0-f172.google.com (mail-wi0-f172.google.com [209.85.212.172]) (using TLSv1 with cipher ECDHE-RSA-RC4-SHA (128/128 bits)) (Client CN "smtp.gmail.com", Issuer "Google Internet Authority G2" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id D48E68C5 for ; Tue, 28 Oct 2014 19:09:02 +0000 (UTC) Received: by mail-wi0-f172.google.com with SMTP id d1so6784789wiv.5 for ; Tue, 28 Oct 2014 12:08:55 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20130820; h=x-gm-message-state:mime-version:in-reply-to:references:date :message-id:subject:from:to:cc:content-type; bh=6FRzJoOVNOUFuOGArqbf4//w3RCXGBJhqhUTiiEe/nY=; b=MjeLwnfx7IveNhVaS2UDK8KcDaDaC2ADUXWk/miyYbvTeRcEpHGPBo1Vz1iv6N3Fow hRVFFs0RU7owO9O8JSjY+paVw7AXJY+kY8pjL+RLoc5+QxAxBqjyr9ZanZqR9tfF09BX 8M4wS4TvsoTfBuzpvwTr/1vAEqsccXXWGWD0R8/Ug3ZRhJcKKnOTHdNPKISjXepQQO2o f3ApWBHQjFzc10TPLXszi+kgl/HbokKJRdq44zvrSpRUqV7+OvrkMHLdCWvP+8mwAvKk W8FpyrCf1k7R0FRek3zTPrvVW97+8Vr6IiyfvpZ5y8JwEHSrTXUzsNQ67KPAWkmnpaV8 Z1Vw== X-Gm-Message-State: ALoCoQmuk7ufHYqfmUpceDQBFj9eMPv7kcITom0nBtRPVHtlVeJw2luOZcvTC/IU7+EDXEErnehb MIME-Version: 1.0 X-Received: by 10.181.27.197 with SMTP id ji5mr30589199wid.26.1414523334922; Tue, 28 Oct 2014 12:08:54 -0700 (PDT) Received: by 10.180.10.71 with HTTP; Tue, 28 Oct 2014 12:08:54 -0700 (PDT) In-Reply-To: <20141028130146.6d2b6179@gumby.homeunix.com> References: <0fdf2022075b7a33f0abde4edd7c12a1@paz.bz> <20141028130146.6d2b6179@gumby.homeunix.com> Date: Tue, 28 Oct 2014 12:08:54 -0700 Message-ID: Subject: Re: out of swap space From: "Reed A. Cartwright" To: RW Content-Type: text/plain; charset=UTF-8 Cc: "freebsd-questions@freebsd.org" X-BeenThere: freebsd-questions@freebsd.org X-Mailman-Version: 2.1.18-1 Precedence: list List-Id: User questions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 28 Oct 2014 19:09:03 -0000 We've run out of swap on a system with 512GB of memory and 1TB of swap space. Processes get killed, including services. It is usually easiest to reboot to start from a fresh system. The funny effect is that you can log in to SSH and get a shell, but cannot run any binary that is not already cached in memory. That confused the hell out of me until I checked memory and swap usage. On Tue, Oct 28, 2014 at 6:01 AM, RW wrote: > On Mon, 27 Oct 2014 16:39:52 -0500 > Adam Vande More wrote: > >> On Mon, Oct 27, 2014 at 2:57 PM, Jim Pazarena wrote: >> >> > There is a lot of historical chatter about the amount of swap space >> > required. >> > But for my question, I haven't seen discussion: >> > What HAPPENS when the system flags "out of swap space". >> > Does a process die? or does the system merely become very sluggish? >> > >> >> Both, a process is killed and whenever you're starting to use swap >> space you should expect the system to become sluggish. > > I don't know that anything bad happens simply because you run out of > swap. Processes are killed when the system is unable to find enough > memory to carry on. > > For example if you have 4GB of RAM and 1GB of swap, and you leave 2GB > on tmpfs, you may fill swap without even coming close to running out of > memory. Another example is a very slow memory leak where running out of > memory could happen a long time after running out of swap. > > There seems to be a common trend of allocating swap space that's much > smaller than RAM. When you combine that with tmpfs use, I suspect it > may have become much more common to run out of swap without > consequences. > _______________________________________________ > freebsd-questions@freebsd.org mailing list > http://lists.freebsd.org/mailman/listinfo/freebsd-questions > To unsubscribe, send any mail to "freebsd-questions-unsubscribe@freebsd.org" -- Reed A. Cartwright, PhD Barrett Honors Faculty Assistant Professor of Genomics, Evolution, and Bioinformatics School of Life Sciences Center for Evolutionary Medicine and Informatics The Biodesign Institute Arizona State University ================== Address: The Biodesign Institute, PO Box 875301, Tempe, AZ 85287-5301 USA Packages: The Biodesign Institute, 1001 S. McAllister Ave, Tempe, AZ 85287-5301 USA Office: Biodesign A-224A, 1-480-965-9949 Website: http://cartwrig.ht/