From owner-freebsd-fs@freebsd.org Fri Aug 26 15:48:53 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 44D55B70FA2 for ; Fri, 26 Aug 2016 15:48:53 +0000 (UTC) (envelope-from ben.rubson@gmail.com) Received: from mail-wm0-x232.google.com (mail-wm0-x232.google.com [IPv6:2a00:1450:400c:c09::232]) (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 C9FABC10 for ; Fri, 26 Aug 2016 15:48:52 +0000 (UTC) (envelope-from ben.rubson@gmail.com) Received: by mail-wm0-x232.google.com with SMTP id q128so284659976wma.1 for ; Fri, 26 Aug 2016 08:48:52 -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=V8gruszECuHkNICP5A7V68TwdukGZC5YwKvzek4mh8E=; b=s+j1cIVMHLCJ3riZgZY2CQDYGOjPxQOYantF9WpMnNQGqHbwHu3PoBzH1qj3uO0Azh hxQPAgYJTcIM+g7e6SA3Uc/mjVSUuOx4sRpypkIimP/L5+gSJ37s6tHcDaPWkB5hPGI5 qw/LU+g6asHiPmA1Y3BF9bVUVlRgY0HPc/9ucpWAFLJxfVlo1CguMSxoQYxmY6x+K/IQ BgiwVXryqOJsMZ9GcAkCppaJJS0C0pl0kHxWL0bJ3a8DiOd1UgcEeaf5o3GtD3dTikM/ qclPa27IzZoCACGazjSG7GonN1TqkyI4JXg4P2Q7LZFhfVv5UGejbPFmjEuhdspVxGMu vLmA== 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=V8gruszECuHkNICP5A7V68TwdukGZC5YwKvzek4mh8E=; b=O9WgmTT2NUm6KALozmzRkEfn5Mky1s5GYeLTws19wxp0IGqeA32/wuebZVR80NVV7V 24HMPf1M1BkrSHn3D73G9oCLv3P0p0CpuCIBkuhz/zNYCgpZBpW709OetwkGU3mAKKbd gnErQgJb2an038+ZsXZsa0oWTQkTf6X9VI+94+rMMevCwqecvqBR9GldSA6uJxdnmrCM VKj7oT+kujhwXaab7fAn7C+HDvBqo3l+psU8104Y67+N/rJQGSsGqlnotkaeBhrp+ceT Imgz6zUaEx+6S4TU93dOlL6uZmUUoBytcPPn5EKHM42ggUZC2ObGFRgOXgaJ8u84OB+A XWrg== X-Gm-Message-State: AE9vXwODLNP6LkXpD++tjo+XfCV0HkMLeiplAQBtDjOe6NX9qC9lnDOLefNFlbyczP2OPA== X-Received: by 10.194.60.2 with SMTP id d2mr5010239wjr.179.1472226531013; Fri, 26 Aug 2016 08:48:51 -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 o142sm44307494wme.20.2016.08.26.08.48.50 for (version=TLS1 cipher=ECDHE-RSA-AES128-SHA bits=128/128); Fri, 26 Aug 2016 08:48:50 -0700 (PDT) Content-Type: text/plain; charset=us-ascii Mime-Version: 1.0 (Mac OS X Mail 9.3 \(3124\)) Subject: Re: [ZFS] ARC accounting bug ? From: Ben RUBSON In-Reply-To: <453b967d-4139-c6b6-a27a-223ed4d92c74@kateley.com> Date: Fri, 26 Aug 2016 17:48:49 +0200 Content-Transfer-Encoding: quoted-printable Message-Id: 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> <9A3B2699-B077-4F72-90A5-63D7E22BE652@gmail.com> <453b967d-4139-c6b6-a27a-223ed4d92c74@kateley.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 15:48:53 -0000 Linda, Thank you very much for your suggestion. However atime is off on my pool. > On 26 Aug 2016, at 17:46, Linda Kateley wrote: >=20 > Metadata updates when you access a file. Atime is most often updated = and you will miss. >=20 > If you are running vm's on zfs I always recommend to turn off atime = updates. >=20 > Metadata is usually tiny so you probably won't see disk activity >=20 >=20 > On 8/26/16 10:27 AM, Ben RUBSON wrote: >> 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. >>=20 >> I would really be glad if you could enlighten me :) >>=20 >> Many thanks again, >>=20 >> Ben >>=20 >>=20 >>=20 >>> 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 >> _______________________________________________ >> freebsd-fs@freebsd.org mailing list >> https://lists.freebsd.org/mailman/listinfo/freebsd-fs >> To unsubscribe, send any mail to "freebsd-fs-unsubscribe@freebsd.org" >=20 > _______________________________________________ > freebsd-fs@freebsd.org mailing list > https://lists.freebsd.org/mailman/listinfo/freebsd-fs > To unsubscribe, send any mail to "freebsd-fs-unsubscribe@freebsd.org"