From owner-freebsd-fs@freebsd.org Thu Jul 30 14:41:23 2015 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 A24099AF774 for ; Thu, 30 Jul 2015 14:41:23 +0000 (UTC) (envelope-from paul@kraus-haus.org) Received: from mail-qg0-f54.google.com (mail-qg0-f54.google.com [209.85.192.54]) (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 64EF4DC9 for ; Thu, 30 Jul 2015 14:41:23 +0000 (UTC) (envelope-from paul@kraus-haus.org) Received: by qgii95 with SMTP id i95so25438501qgi.2 for ; Thu, 30 Jul 2015 07:41:22 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20130820; h=x-gm-message-state:content-type:mime-version:subject:from :in-reply-to:date:content-transfer-encoding:message-id:references:to; bh=nglfaL0Asb6tmuOYaaY4EsNjhtq8TkM+79tN2D0Ij/0=; b=kar7fvq5m9sTWq0ratWI2OtqhpVLHvIWcau8HYx/KsZ73ppTX2oAKzK9v4f3Q1BsZA AZQv1/kv5z32erelO5jEGXTkF6gMp1YT+7Ur6SM6wkHfXJ8ZpjFJUjT1d0vF51598W2W dBR81xZ4TLRDqxS9r3IZBMruwNxieBVPQ/bVxnYBJSHgdtrZMb5oIrvBH8wIytckyNwU XphucEn9/jGLah2ZZ9JXa1KS4l6k11HKHncPyBoJNgTO+37stq02jBI9qQk3U5hHhQe4 niSo/PNKKiBmrjj8E3L8qYfw1qRNIH2pb79s/fzZhdDGhiycaAIQWWwpkDlpW5/e8VGC cDSA== X-Gm-Message-State: ALoCoQl555dNoN//yyynblrPeRxO/aT8MUCxNTgGY3JaWJCyRZ9ZkBzizkI20NkQgAxGPMEZAESq X-Received: by 10.140.201.204 with SMTP id w195mr6013114qha.16.1438267282166; Thu, 30 Jul 2015 07:41:22 -0700 (PDT) Received: from mbp-1.thecreativeadvantage.com (mail.thecreativeadvantage.com. [96.236.20.34]) by smtp.gmail.com with ESMTPSA id 34sm545986qkz.38.2015.07.30.07.41.20 (version=TLSv1 cipher=ECDHE-RSA-RC4-SHA bits=128/128); Thu, 30 Jul 2015 07:41:20 -0700 (PDT) Content-Type: text/plain; charset=us-ascii Mime-Version: 1.0 (Mac OS X Mail 7.3 \(1878.6\)) Subject: Re: ZFS on 10-STABLE r281159: programs, accessing ZFS pauses for minutes in state [*kmem arena] From: Paul Kraus In-Reply-To: <55BA0F41.6070508@multiplay.co.uk> Date: Thu, 30 Jul 2015 10:41:19 -0400 Content-Transfer-Encoding: quoted-printable Message-Id: <26DA7547-3258-44CC-A3EA-338AFA13640E@kraus-haus.org> References: <164833736.20150730143008@serebryakov.spb.ru> <55BA0F41.6070508@multiplay.co.uk> To: FreeBSD Filesystems X-Mailer: Apple Mail (2.1878.6) X-BeenThere: freebsd-fs@freebsd.org X-Mailman-Version: 2.1.20 Precedence: list List-Id: Filesystems List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 30 Jul 2015 14:41:23 -0000 On Jul 30, 2015, at 7:49, Steven Hartland = wrote: > On 30/07/2015 12:30, Lev Serebryakov wrote: >>=20 >> Deduplication IS TURNED OFF. atime is turned off. Record size set to = 1M as >> I have a lot of big files (movies, RAW photo from DSLR, etc). = Compression is >> turned off. > You don't need to do that as record set size is a min not a max, if = you don't force it large files will still be stored efficiently. Can you point to documentation for that ? I really hope that the 128KB default is not a minimum record size or a = 1KB file will take up 128 KB of FS space. As far as I know, zfs recordsize has always, since the very beginning of = ZFS under Solaris, been the MAX recrodsize, but it is also a hint and = not a fixed value. ZFS will write any size records (powers of 2) from = 512 bytes (4 KB in the case of an shift =3D 4 pool) up to recordsize. = Tuning of recordsize has been frowned upon since the beginning unless = you _know_ the size of your writes and they are fixed (like 8 KB = database records).=20 Also note that ZFS will fit the write to the pool in the case of = RAIDz, see Matt Ahrens bloig entry here: = http://blog.delphix.com/matt/2014/06/06/zfs-stripe-width/ -- Paul Kraus paul@kraus-haus.org