From owner-freebsd-questions@FreeBSD.ORG Tue Jul 22 18:02:21 2014 Return-Path: Delivered-To: freebsd-questions@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [8.8.178.115]) (using TLSv1 with cipher ADH-AES256-SHA (256/256 bits)) (No client certificate requested) by hub.freebsd.org (Postfix) with ESMTPS id E5C66489 for ; Tue, 22 Jul 2014 18:02:21 +0000 (UTC) Received: from nm39-vm2.bullet.mail.ir2.yahoo.com (nm39-vm2.bullet.mail.ir2.yahoo.com [212.82.97.161]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (Client did not present a certificate) by mx1.freebsd.org (Postfix) with ESMTPS id 2136F228A for ; Tue, 22 Jul 2014 18:02:20 +0000 (UTC) Received: from [212.82.98.51] by nm39.bullet.mail.ir2.yahoo.com with NNFMP; 22 Jul 2014 18:02:13 -0000 Received: from [46.228.39.80] by tm4.bullet.mail.ir2.yahoo.com with NNFMP; 22 Jul 2014 18:02:13 -0000 Received: from [127.0.0.1] by smtp117.mail.ir2.yahoo.com with NNFMP; 22 Jul 2014 18:02:13 -0000 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=rocketmail.com; s=s1024; t=1406052133; bh=xkiuhkbmiSoPyQfTSMFFxt/t9q5OtZN/cb9uQ8msgIs=; h=X-Yahoo-Newman-Id:X-Yahoo-Newman-Property:X-YMail-OSG:X-Yahoo-SMTP:Message-ID:Subject:From:To:Date:In-Reply-To:References:Content-Type:X-Mailer:Mime-Version:Content-Transfer-Encoding; b=K24yyz0ViSb9K9zyd2UgPO9dNugm/9lfOP1wPa5L56Z+Js9QvNP+7QVNj92Z6raa353DSoNji3HAQfu/7/HkUnljpLJnZ6KCzPMxv7cDb2oT2fKVVA/U1EFpoM0xhd8UL8nB1jkElWXm9XgqAzhLyu9Yb834kxyKRwDABLgonA4= X-Yahoo-Newman-Id: 58075.80521.bm@smtp117.mail.ir2.yahoo.com X-Yahoo-Newman-Property: ymail-3 X-YMail-OSG: Lw88QxwVM1lt74QO5Gs7xPr2vVdwwNyUXVMt_uYmSQfBypw aeEL4fpuQ_RRm1BeSCE3jQ..KAJlvfXr4boSorYNqhf.ilW8Nk52UCcTPhR0 TT5Si2ofmV6P1QemZINgkmyJ42NCEAcGGK21Gw1rAOZYJKr2e9syZlWI4Vx5 RESBDD7cuod04_0xYJtFtkiO4D4w1MF3DQgfZ0MOoaRPUzg9khi0Y8jH7DM1 CO6QxXYR2KSkHM0dChuAAyprp6e8FJhHtX9rsiq.poh3OozkVQHUCqUeQqaU 1uK5C31U.h8FOrJzaCtOtS.GePQKKDMbrjLN3UbFD55CRPmW5oLPjxg5Q9Kc qeUZTHIE_G7jKqqzeYuFHti8MwFT4iLiyOhrKd8MnjMtT7ntIL00ZT3Zqyzw mycUVAo9at_sifp2D8JBs.lCVkqSaBHve1UYxFPJWEtyAtWvna8jLDc7wIZ_ MhB9Gw.rwwUlf2DuPr8H99ZSjNL5BNqbhweXQC3NT02Us6HEm5aQxprLiEi8 xMYGZMcAB44rLMh931NRiq70QmyPmba5P46vUnU86iKuAvx_W70qpa4IhvQZ e_gU91bQfpYTNZSlhtDqom.CGeDpdxcn.5xq6tR8fmJZVhXDSpXmwqUs2hmu 0uFqNI7ZjuVw- X-Yahoo-SMTP: BeMCPs2swBABTJ3kAeEiC_hE0mz8jRexLddJfD8pI2j32fOacjBmXg-- Message-ID: <1406052132.7452.7.camel@rocketmail.com> Subject: Re: [Bulk] Re: How much swap space for a 32 GB RAM system? From: Ralf Mardorf To: freebsd-questions@freebsd.org Date: Tue, 22 Jul 2014 20:02:12 +0200 In-Reply-To: References: <53CE8BB8.7030303@qeng-ho.org> <53CE8F62.8090701@tysdomain.com> Content-Type: text/plain; charset="UTF-8" X-Mailer: Evolution 3.12.4 Mime-Version: 1.0 Content-Transfer-Encoding: 7bit X-BeenThere: freebsd-questions@freebsd.org X-Mailman-Version: 2.1.18 Precedence: list List-Id: User questions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 22 Jul 2014 18:02:22 -0000 On Tue, 2014-07-22 at 13:35 -0400, Michael Powell wrote: > Since I don't use such things (me sysadmin - not a coder) I'm not as > knowledgeable, but I seem to recall that a crash dump needs a swap > that is as large as physical memory. "My 48GB swap file system isn't fully recognized. Q. What is the max amount of swap a system can use? A. Are you sure you want/need that much swap anyway? The old-school 2-4x RAM doesn't really apply, though you may want a bit more than 1x physical RAM if you are capturing a crash dump, and some systems have >32GB RAM now. Swap can be limited by kern.maxswzone which controls the size of metadata use to track swap (8.X default is 64MB allowing ~15GB of swap). Note other changes are required to have >8x physical RAM for swap." - https://commons.lbl.gov/display/~jwelcher@lbl.gov/FreeBSD +Random+FAQ Interesting thread, since there isn't an answer for Linux and I plan to use a new FreeBSD install in the close future too.