From owner-freebsd-fs@freebsd.org Sat Aug 1 16:06:20 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 23A739AFC88 for ; Sat, 1 Aug 2015 16:06:20 +0000 (UTC) (envelope-from artemb@gmail.com) Received: from mail-oi0-x22e.google.com (mail-oi0-x22e.google.com [IPv6:2607:f8b0:4003:c06::22e]) (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 DFC0B908 for ; Sat, 1 Aug 2015 16:06:19 +0000 (UTC) (envelope-from artemb@gmail.com) Received: by oig1 with SMTP id 1so18396525oig.0 for ; Sat, 01 Aug 2015 09:06:18 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=mime-version:sender:in-reply-to:references:date:message-id:subject :from:to:cc:content-type; bh=UBavg02ghKVLoLGQZJml0dWJabfya/HDBr0GIRmsvU4=; b=ADZWHPLZMiE5kdHJ+IhyxtZIqnsWc3U4WU8OiTwcbg3S3zTC2VuPVcKRrx0tp1fczS 8dlaT6bx0jzf4xQ+ua0J8qspkB6+4ofBM/kHE1U1EJ3FRqRu2rh3e2G3JiuCVCPmxf5F dio3hbqihE+7b11ZnPVXXl7j/qfzJICv6kVK5N/W3w0p2GRcljJx5f8FSX8T0nxJh8ol FDwGuUnxL418CT4FQSmfYGu4ddZm+R/UtcbvzcR1YxgndXVe+SwyMYaFbK+LHU64rBPd j6S3PtwDT0I8zWZDfn8qFMbE7lpum3vV38Akxe89lazDHp3SwB+uTesiEm0vyezdsAnx OrAA== MIME-Version: 1.0 X-Received: by 10.202.170.66 with SMTP id t63mr8686550oie.40.1438445178702; Sat, 01 Aug 2015 09:06:18 -0700 (PDT) Sender: artemb@gmail.com Received: by 10.202.23.132 with HTTP; Sat, 1 Aug 2015 09:06:18 -0700 (PDT) In-Reply-To: <55BCE1C3.50307@sneakertech.com> References: <55BC14B7.9010009@sneakertech.com> <20150801133635.00002ecc@Leidinger.net> <55BCE1C3.50307@sneakertech.com> Date: Sat, 1 Aug 2015 09:06:18 -0700 X-Google-Sender-Auth: A9r4UANt4a73TyyeJSeuKtIXsME Message-ID: Subject: Re: ZFS: Disabling ARC? From: Artem Belevich To: Quartz Cc: FreeBSD FS Content-Type: text/plain; charset=UTF-8 X-Content-Filtered-By: Mailman/MimeDel 2.1.20 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: Sat, 01 Aug 2015 16:06:20 -0000 On Sat, Aug 1, 2015 at 8:12 AM, Quartz wrote: > You can tune how the ARC is used: >> > > I know *how* to tune it, what I don't know is *when*. Basically, under > what sorts of use cases would I want to mess with it, and why? Given my > contrived media server example, would adjusting the ARC for those datasets > make a noticeable difference either way? Measure it. Find something that matters to you and see whether particular ARC parameters make any difference in *your* workload. --Artem