From owner-freebsd-stable@FreeBSD.ORG Fri Feb 12 19:36:42 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 77C7A106566C for ; Fri, 12 Feb 2010 19:36:42 +0000 (UTC) (envelope-from korvus@comcast.net) Received: from mx04.pub.collaborativefusion.com (mx04.pub.collaborativefusion.com [206.210.72.84]) by mx1.freebsd.org (Postfix) with ESMTP id 42CE38FC15 for ; Fri, 12 Feb 2010 19:36:41 +0000 (UTC) Received: from reflector.ws.pitbpa0.priv.collaborativefusion.com ([206.210.89.202]) by mx04.pub.collaborativefusion.com (StrongMail Enterprise 4.1.1.4(4.1.1.4-47689)); Fri, 12 Feb 2010 14:58:58 -0500 X-VirtualServerGroup: Default X-MailingID: 00000::00000::00000::00000::::322 X-SMHeaderMap: mid="X-MailingID" X-Destination-ID: freebsd-stable@freebsd.org X-SMFBL: ZnJlZWJzZC1zdGFibGVAZnJlZWJzZC5vcmc= Message-ID: <4B75ADC7.6000308@comcast.net> Date: Fri, 12 Feb 2010 14:36:39 -0500 From: Steve Polyack User-Agent: Mozilla/5.0 (X11; U; FreeBSD amd64; en-US; rv:1.9.1.7) Gecko/20100211 Thunderbird/3.0.1 MIME-Version: 1.0 To: Artem Belevich References: <4B759E70.4030809@comcast.net> In-Reply-To: Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit 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 19:36:42 -0000 On 02/12/10 13:47, Artem Belevich wrote: > On Fri, Feb 12, 2010 at 10:31 AM, Steve Polyack wrote: > > >> Has anyone had an issue with the ZFS ARC max being limited below what has >> been defined in /boot/loader.conf? I 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: >> vfs.zfs.arc_max="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. For >> reference, I'm running 8-STABLE (as of Jan 19th) on an amd64 system with 8GB >> of RAM. The system was previously very stable with 4GB of RAM and a 512MB >> arc_max. I have not modified vm.kmem_size_max (defaults to ~330GB on amd64) >> or any other ZFS tunables. I'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.org" >> >> > > 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. At 330GB it is way above and beyond what will ever be allocated to ARC: $ sysctl vm.kmem_size_max vm.kmem_size_max: 329853485875