From owner-freebsd-fs@freebsd.org Fri Aug 26 15:27:23 2016 Return-Path: Delivered-To: freebsd-fs@mailman.ysv.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:1900:2254:206a::19:1]) by mailman.ysv.freebsd.org (Postfix) with ESMTP id C8082B70AE3 for ; Fri, 26 Aug 2016 15:27:23 +0000 (UTC) (envelope-from ben.rubson@gmail.com) Received: from mail-wm0-x22c.google.com (mail-wm0-x22c.google.com [IPv6:2a00:1450:400c:c09::22c]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (Client CN "smtp.gmail.com", Issuer "Google Internet Authority G2" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id 5A0DEED3 for ; Fri, 26 Aug 2016 15:27:23 +0000 (UTC) (envelope-from ben.rubson@gmail.com) Received: by mail-wm0-x22c.google.com with SMTP id i5so124771576wmg.0 for ; Fri, 26 Aug 2016 08:27:23 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=mime-version:subject:from:in-reply-to:date :content-transfer-encoding:message-id:references:to; bh=N9UIWd19qYFtJWZ/ivHMEkKndLfUD3I+mgnGCWLCLB8=; b=Nw/oSxLe15lPNNaVQL5j8xBB7E4KGXZO/LpvkBEiE8/yQlyJok0DY+QaR8mH2GYmit hhZr2lMLCxUEwBROKgtAEch4CsukvObcANNXnk9gw1t4cb7VESLTEqAiVgevkA8Zkc3c DGLcd65S27o9Dk4ZorsLe2y+1qCcEldKzowvCS2Rl5oH6oAgxvAC9LdgQnIyDieGhruW aY6JGpNCgSyY1rGDRF/s5fJOwvoj9mffgPfwmflyw4A5jQ+Cs0G+jKbB0xzdsDhXRDxc 4dTflColNB8+hHUqxOj8nbGx7PStxHLK/m7ZyRG2wcjCjQ6VRyfrIUBOH5ZtSOHInD/e E28Q== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20130820; h=x-gm-message-state:mime-version:subject:from:in-reply-to:date :content-transfer-encoding:message-id:references:to; bh=N9UIWd19qYFtJWZ/ivHMEkKndLfUD3I+mgnGCWLCLB8=; b=XTdW8ANl/22IrBLqmGrxdwx+o4Hlk6Y5fBYZvQd+2dycd4yl/bBa0kpJViWprYJiXI 66qaL8aAzGqyuyR3Q5535wPpDCGwqTG8TfKLHRP4iIMIbPTvTYrXMyJho5kH0ifOiVW/ IV32+vpH1sXnpsv1LXj2zOHQZePnA5jpfjenZ+kxxQq0XbAROnmv6hSre66UFPJgNy1g wpQwGLmFq6rDLVrT7nbnFMHNnIhOTNOUQcPOusVj/C30nxiv9P9Ioe77JqaEXt7xuHVd DGphsOIjDGX5hBH0qNg60WcQ2yMFOacYx88EMlkyqC+jMEF7EdYSIm01yvL2PUahgEmJ Vegw== X-Gm-Message-State: AE9vXwOQYCLR+XPujr8od7OFpdt3qyEYf6LnFOh64X0+g1N1//M+UELbxzY2Y94rm1Xtmw== X-Received: by 10.194.187.134 with SMTP id fs6mr4660895wjc.3.1472225241302; Fri, 26 Aug 2016 08:27:21 -0700 (PDT) Received: from macbook-air-de-benjamin-1.home (ANice-651-1-19-245.w86-203.abo.wanadoo.fr. [86.203.34.245]) by smtp.gmail.com with ESMTPSA id e5sm44129665wma.13.2016.08.26.08.27.20 for (version=TLS1 cipher=ECDHE-RSA-AES128-SHA bits=128/128); Fri, 26 Aug 2016 08:27:20 -0700 (PDT) Content-Type: text/plain; charset=windows-1252 Mime-Version: 1.0 (Mac OS X Mail 9.3 \(3124\)) Subject: Re: [ZFS] ARC accounting bug ? From: Ben RUBSON In-Reply-To: <91665D7B-D2EA-4A7F-BE8D-67BE238DAF6B@gmail.com> Date: Fri, 26 Aug 2016 17:27:19 +0200 Content-Transfer-Encoding: quoted-printable Message-Id: <9A3B2699-B077-4F72-90A5-63D7E22BE652@gmail.com> References: <5B8C6663-5D21-4C03-AC69-CB7E70D3A6C2@gmail.com> <067ac0ed-1f2d-c9fb-de4d-ed5da62fe10c@internetx.com> <9EAAEEC5-0FFF-474D-9AD0-4447CD6B549B@gmail.com> <91665D7B-D2EA-4A7F-BE8D-67BE238DAF6B@gmail.com> To: FreeBSD FS X-Mailer: Apple Mail (2.3124) X-BeenThere: freebsd-fs@freebsd.org X-Mailman-Version: 2.1.22 Precedence: list List-Id: Filesystems List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 26 Aug 2016 15:27:23 -0000 I'm sorry but I still can't find out where do these ARC demand metadata = misses come from. In addition, why they are not cached, as my ARC is 1% used. And why I don't see any disk activity to honour them. I would really be glad if you could enlighten me :) Many thanks again, Ben > On 26 Aug 2016, at 14:28, Ben RUBSON wrote: >=20 > Yes Juergen, metadata only stores in ARC files' info (location in pool = and some other useful info), not the user data. >=20 > I think "find" only needs metadata, as it does not read the files' = content. > Which can be "verified" because : > - there is no IO at all on the pool (after the first find loop, once = ARC has the needed metadata) ; > - there is no ARC demand data at all. > But I may be wrong, so of course feel free to correct me. Thank you. >=20 > Thank you for the links, I already read them before posting here, but = I may have missed something. >=20 > Ben >=20 >> On 26 Aug 2016, at 14:16, InterNetX - Juergen Gotteswinter = wrote: >>=20 >> so, you know the difference between >>=20 >> - metadata >> - data >>=20 >> ? >>=20 >> if yes, what is your find actually doing in this case? >>=20 >> regarding arc >>=20 >> http://dtrace.org/blogs/brendan/2012/01/09/activity-of-the-zfs-arc/ >> = https://www.patpro.net/blog/index.php/2014/03/19/2628-zfs-primarycache-all= -versus-metadata/ >>=20 >>=20 >>=20 >> Am 26.08.2016 um 14:06 schrieb Ben RUBSON: >>> Juergen, thank you for your answer. >>> So where do you think these ARC misses come from ? I can't find out = :S >>> Thank you ! >>>=20 >>>> On 26 Aug 2016, at 14:01, InterNetX - Juergen Gotteswinter = wrote: >>>>=20 >>>> no bug, everything like i whould expect >>>>=20 >>>> Am 26.08.2016 um 11:40 schrieb Ben RUBSON: >>>>> uname -v >>>>> FreeBSD 11.0-RC2 #0 r304729: Wed Aug 24 06:59:03 UTC 2016 = root@releng2.nyi.freebsd.org:/usr/obj/usr/src/sys/GENERIC