From owner-freebsd-stable@FreeBSD.ORG Fri Feb 12 21:10:54 2010 Return-Path: Delivered-To: freebsd-stable@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 568361065696; Fri, 12 Feb 2010 21:10:54 +0000 (UTC) (envelope-from artemb@gmail.com) Received: from mail-iw0-f194.google.com (mail-iw0-f194.google.com [209.85.223.194]) by mx1.freebsd.org (Postfix) with ESMTP id 0181C8FC22; Fri, 12 Feb 2010 21:10:53 +0000 (UTC) Received: by iwn32 with SMTP id 32so4194479iwn.14 for ; Fri, 12 Feb 2010 13:10:53 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma; h=domainkey-signature:mime-version:sender:received:in-reply-to :references:date:x-google-sender-auth:message-id:subject:from:to:cc :content-type:content-transfer-encoding; bh=FYgMknWhea0eXc2bUza6On4QhmBItJpIcQAK/3J1Y8c=; b=h2HUFalGqkIqzyosiD0qeN6/NCCUEOic11SF9pytboviOUzTUS0OOg9ERupLuASSnx DJWbatkwQYO6WA1l/aJ70vRi8rL562CJSoTi75q0b2lFfU7NpZwdVsd64esEy4eEmm4i /1F7MfUJoS+YVmYt5mFMdC3kygf4nLxfeTifI= DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=mime-version:sender:in-reply-to:references:date :x-google-sender-auth:message-id:subject:from:to:cc:content-type :content-transfer-encoding; b=D8TxuAEnDV5QD/DaEHYtFfgacLZfhNuj7I1uI11giVyhC+qefghsq+hwQh9Tdol8B5 TnhSYviKCJQymzXI7m6it3ETJCt20GjNWs37aSpCtNxEELH12v53aiRP6hfmazRYqzrX uQyY/wZzsqAVqBt8JL+qTc/F3go6lsUVnNlIE= MIME-Version: 1.0 Sender: artemb@gmail.com Received: by 10.231.154.77 with SMTP id n13mr1285922ibw.11.1266009051736; Fri, 12 Feb 2010 13:10:51 -0800 (PST) In-Reply-To: <4B75ADC7.6000308@comcast.net> References: <4B759E70.4030809@comcast.net> <4B75ADC7.6000308@comcast.net> Date: Fri, 12 Feb 2010 13:10:51 -0800 X-Google-Sender-Auth: fb3ee935a576a21d Message-ID: From: Artem Belevich To: Steve Polyack Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable Cc: freebsd-fs@freebsd.org, freebsd-stable Subject: Re: ZFS ARC being limited below what is defined in /boot/loader.conf X-BeenThere: freebsd-stable@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Production branch of FreeBSD source code List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 12 Feb 2010 21:10:54 -0000 vm.kmem_size_max/vm.kmem_size_min define the range vm.kmem_size can be set = to. vm_kmem_size specifies the actual kmem size. ARC size in turn limited by vm.kmem_size. If you want to bump ARC size, you do need to bump vm.kmem_size. --Artem On Fri, Feb 12, 2010 at 11:36 AM, Steve Polyack wrote: > On 02/12/10 13:47, Artem Belevich wrote: >> >> On Fri, Feb 12, 2010 at 10:31 AM, Steve Polyack >> =A0wrote: >> >> >>> >>> Has anyone had an issue with the ZFS ARC max being limited below what h= as >>> been defined in /boot/loader.conf? =A0I just upgraded the RAM in a >>> ZFS-equipped system and attempted to devote 4GB to the ARC cache by >>> placing >>> the following in loader.conf: >>> =A0vfs.zfs.arc_max=3D"4096M" >>> >>> However, after rebooting, querying the sysctl gives me this: >>> $ sysctl vfs.zfs.arc_max >>> vfs.zfs.arc_max: 1726489600 >>> >>> or about 1.7GB, an odd number that I can't find any references to. =A0F= or >>> reference, I'm running 8-STABLE (as of Jan 19th) on an amd64 system wit= h >>> 8GB >>> of RAM. =A0The system was previously very stable with 4GB of RAM and a >>> 512MB >>> arc_max. =A0I have not modified vm.kmem_size_max (defaults to ~330GB on >>> amd64) >>> or any other ZFS tunables. =A0I'd also like to avoid syncing up to the >>> current >>> 8-STABLE if at all possible. >>> >>> Thanks, >>> Steve Polyack >>> >>> _______________________________________________ >>> freebsd-stable@freebsd.org mailing list >>> http://lists.freebsd.org/mailman/listinfo/freebsd-stable >>> To unsubscribe, send any mail to "freebsd-stable-unsubscribe@freebsd.or= g" >>> >>> >> >> Check your vm.kmem_size. Default setting is way too low. Set it to at >> least double of desired arc size. >> >> --Artem > > I mentioned it briefly, but vm.kmem_size_max was left at the default for > amd64. =A0At 330GB it is way above and beyond what will ever be allocated= to > ARC: > $ sysctl vm.kmem_size_max > vm.kmem_size_max: 329853485875 > > >