From owner-freebsd-hackers@FreeBSD.ORG Sat Jan 23 09:44:40 2010 Return-Path: Delivered-To: freebsd-hackers@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 155AE106566C for ; Sat, 23 Jan 2010 09:44:40 +0000 (UTC) (envelope-from alexander@leidinger.net) Received: from mail.ebusiness-leidinger.de (mail.ebusiness-leidinger.de [217.11.53.44]) by mx1.freebsd.org (Postfix) with ESMTP id AE68F8FC0C for ; Sat, 23 Jan 2010 09:44:39 +0000 (UTC) Received: from outgoing.leidinger.net (pD9E2CA42.dip.t-dialin.net [217.226.202.66]) by mail.ebusiness-leidinger.de (Postfix) with ESMTPSA id 57FFA84515E; Sat, 23 Jan 2010 10:44:33 +0100 (CET) Received: from unknown (unknown [192.168.2.110]) by outgoing.leidinger.net (Postfix) with ESMTP id 32FA623555B; Sat, 23 Jan 2010 10:44:30 +0100 (CET) Date: Sat, 23 Jan 2010 10:44:28 +0100 From: Alexander Leidinger To: jhell Message-ID: <20100123104428.000021b5@unknown> In-Reply-To: References: <7f14551c1001190119x46c6b04dx2362cd1252f0d81@mail.gmail.com> <7f14551c1001190216w49814186n1ada2b721380502b@mail.gmail.com> <4B55C5A6.2020109@DataIX.net> <20100120111433.25801pnmhrxnirok@webmail.leidinger.net> X-Mailer: Claws Mail 3.7.2cvs15 (GTK+ 2.16.0; i586-pc-mingw32msvc) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit X-EBL-MailScanner-Information: Please contact the ISP for more information X-EBL-MailScanner-ID: 57FFA84515E.9FC50 X-EBL-MailScanner: Found to be clean X-EBL-MailScanner-SpamCheck: not spam, spamhaus-ZEN, SpamAssassin (not cached, score=-1.363, required 6, autolearn=disabled, ALL_TRUSTED -1.44, TW_ZF 0.08) X-EBL-MailScanner-From: alexander@leidinger.net X-EBL-MailScanner-Watermark: 1264844673.92093@+374hwtCd7ONB6WpEGie2g X-EBL-Spam-Status: No X-Mailman-Approved-At: Sat, 23 Jan 2010 12:46:00 +0000 Cc: freebsd-hackers@freebsd.org Subject: Re: Setting "zfs_arc_max" value in FreeBSD 8. X-BeenThere: freebsd-hackers@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Technical Discussions relating to FreeBSD List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sat, 23 Jan 2010 09:44:40 -0000 On Fri, 22 Jan 2010 20:28:09 -0500 jhell wrote: > > On Wed, 20 Jan 2010 05:14, Alexander@ wrote: > > Quoting jhell (from Tue, 19 Jan 2010 09:45:58 > > -0500): > > > >> On 1/19/2010 5:16 AM, Sherin George wrote: > >>> Thanks Ivan :) > >>> > >>> I found It. add following in /boot/loader.conf > >>> > >>> =================== > >>> vfs.zfs.arc_max="10244M" > >>> =================== > > > >> I just thought I would give a shout at this for stable/7 as of last > >> week. I am not sure if this is just me but I had tried to adjust > >> zfs_arc_max and found out that it was unadjusted to my value after > >> the system came back up. > >> > >> Anyone know if it is adjustable on a system with 1024MB of ram ? > >> Is this just being auto calculated by some other value ? > > > > Can you confirm that you made the modification > > in /boot/loader.conf, and that you used the double-quotes around > > the value as shown above? > > > > The code in 7-stable regarding this is the same as in 8-stable and > > 9-current, so if it is done correctly, it has to change accordingly. > Yes, > > The sysctl in question on my machine is/was put in loader.conf with > the double quotes. > > Every time I have set this before I was trying to set it to a value > >= 512M which with the values below must have not been excepted and > >fell back > to 320M. > > If I set this to a value of <= 511M it works fine which leads me to > believe this is limited by some other value listed below ? It can not be bigger than kmem_max. While I do not know if this is checked, it sounds from your description that it is. > dmesg: > real memory = 1072107520 (1022 MB) > avail memory = 1035038720 (987 MB) > > loader.conf: > kern.maxusers="512" << Not sure if this has anything to do It should influence the kmem_max... if you would not change it yourself. > with it. vfs.zfs.arc_min="80M" > vfs.zfs.arc_max="512M" << This fails. stays at 335544320. It needs to be a lot less than kmem_max (the arc is allocated from the kmem, as such it can not exceed kmem_max, and as other parts of the kernel also need kmem, you need to limit the arc size). On a 32bit system with 1 GB RAM I have kmem_size_max set to 512M and arc_max set to 160M. > vm.kmem_size="512M" > vm.kmem_size_max="512M" << Maybe this one. > kern.ipc.semmni="40" > kern.ipc.semmns="300" > kern.maxdsiz="536870912" > kern.maxfiles="16384" Bye, Alexander.