From owner-freebsd-fs@FreeBSD.ORG Thu Apr 8 03:25:58 2010 Return-Path: Delivered-To: freebsd-fs@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id A168E1065741 for ; Thu, 8 Apr 2010 03:25:58 +0000 (UTC) (envelope-from rincebrain@gmail.com) Received: from mail-yw0-f171.google.com (mail-yw0-f171.google.com [209.85.211.171]) by mx1.freebsd.org (Postfix) with ESMTP id 5B1F18FC23 for ; Thu, 8 Apr 2010 03:25:58 +0000 (UTC) Received: by ywh1 with SMTP id 1so895217ywh.3 for ; Wed, 07 Apr 2010 20:25:57 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma; h=domainkey-signature:mime-version:received:in-reply-to:references :date:received:message-id:subject:from:to:cc:content-type :content-transfer-encoding; bh=EQ5ctBqxU0MtbnIFGeuJ9CFHNjk+ThBaVwia+mbUD+8=; b=hcGZP0tIfUAF2YVtruBiSVp1qARpoUyFgdr/NVepf2madEnQxA9r/uCFeb7DFG9GOS k0zlxFGyMyHHLL67h9N9+w5IRBLCf3a2EqwMGf4b4zk+LK5aTADNtK6LuP1su4XFa5ce pZIq9t4Dy9sCf38ifzXodELKrFlvCHG0ytKeM= DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=mime-version:in-reply-to:references:date:message-id:subject:from:to :cc:content-type:content-transfer-encoding; b=daTpCMJgYVzcb1n2LnefBP13lwh3ImWnh8LV8YGQAxs3mjhy/QqibghWcVM9nvI0qG HXJLrdSRkGGX7kFshloyuUieLRQOjRWnN7t5rRPpXdHconj7kyk+L4iJTzE8pfVem6/K 7ep7NoW4F7CKb3iArx68ys2FOVo6rZNbqQLDo= MIME-Version: 1.0 Received: by 10.231.60.197 with HTTP; Wed, 7 Apr 2010 20:25:57 -0700 (PDT) In-Reply-To: <4BBD15E7.5010006@xpam.de> References: <4BBD15E7.5010006@xpam.de> Date: Wed, 7 Apr 2010 23:25:57 -0400 Received: by 10.150.66.15 with SMTP id o15mr9807330yba.74.1270697157368; Wed, 07 Apr 2010 20:25:57 -0700 (PDT) Message-ID: From: Rich To: Adam Nowacki Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable Cc: freebsd-fs@freebsd.org Subject: Re: ZFS arc sizing (maybe related to kern/145229) X-BeenThere: freebsd-fs@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Filesystems List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 08 Apr 2010 03:25:58 -0000 kstat.zfs.misc.arcstats.memory_throttle_count: 673016 Since UFS has no files of any reasonable size on it (it's literally just rootFS)... - Rich On Wed, Apr 7, 2010 at 7:31 PM, Adam Nowacki wrote: > check kstat.zfs.misc.arcstats.memory_throttle_count > This counter is increased every time zfs thinks system is running low on > memory and will force a write flush and reduce arc size to minimum. Bigge= st > problem is that the code is counting only free memory and completely > ignoring other memory that can be immediately freed like cached files fro= m > ufs. This is very easy to trigger on mixed ufs and zfs system by just > reading enough data from ufs to fill its cache, zfs will begin throttling > and will continue doing so even with no further ufs reads or writes. > > Rich wrote: >> >> A datapoint for you: >> Now running 8-STABLE (plus the mbuf leak fix which went in recently), >> here's my ARC stats and ARC sysctl settings after the server was up >> for about a week (5 days) after that: >> ARC Size: >> =A0 =A0 =A0 =A0Current Size: =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0= =A0 =A0 587.49M (arcsize) >> =A0 =A0 =A0 =A0Target Size: (Adaptive) =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 5= 87.63M (c) >> =A0 =A0 =A0 =A0Min Size (Hard Limit): =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 = =A0512.00M (arc_min) >> =A0 =A0 =A0 =A0Max Size (Hard Limit): =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 = =A03072.00M (arc_max) >> >> ARC Size Breakdown: >> =A0 =A0 =A0 =A0Recently Used Cache Size: =A0 =A0 =A0 98.28% =A0577.50M (= p) >> =A0 =A0 =A0 =A0Frequently Used Cache Size: =A0 =A0 1.72% =A0 10.12M (c-p= ) >> >> ARC Efficiency: >> =A0 =A0 =A0 =A0Cache Access Total: =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 = =A0 2602789964 >> =A0 =A0 =A0 =A0Cache Hit Ratio: =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A096.11% = =A02501461882 >> =A0 =A0 =A0 =A0Cache Miss Ratio: =A0 =A0 =A0 =A0 =A0 =A0 =A0 3.89% =A0 1= 01328082 >> =A0 =A0 =A0 =A0Actual Hit Ratio: =A0 =A0 =A0 =A0 =A0 =A0 =A0 87.65% =A02= 281380527 >> >> and >> >> =A0 =A0 =A0 =A0vfs.zfs.arc_meta_limit=3D1073741824 >> =A0 =A0 =A0 =A0vfs.zfs.arc_meta_used=3D548265792 >> =A0 =A0 =A0 =A0vfs.zfs.arc_min=3D536870912 >> =A0 =A0 =A0 =A0vfs.zfs.arc_max=3D3221225472 >> >> So it very clearly limits to near the minimum size, but whether this >> is design or accidental behavior, I'm unsure. >> _______________________________________________ >> freebsd-fs@freebsd.org mailing list >> http://lists.freebsd.org/mailman/listinfo/freebsd-fs >> To unsubscribe, send any mail to "freebsd-fs-unsubscribe@freebsd.org" >> >> > > _______________________________________________ > freebsd-fs@freebsd.org mailing list > http://lists.freebsd.org/mailman/listinfo/freebsd-fs > To unsubscribe, send any mail to "freebsd-fs-unsubscribe@freebsd.org" >