From owner-freebsd-stable@FreeBSD.ORG Tue Nov 16 13:00:49 2010 Return-Path: Delivered-To: freebsd-stable@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id EC34E106566B; Tue, 16 Nov 2010 13:00:49 +0000 (UTC) (envelope-from christer.solskogen@gmail.com) Received: from mail-qy0-f182.google.com (mail-qy0-f182.google.com [209.85.216.182]) by mx1.freebsd.org (Postfix) with ESMTP id 8D3068FC14; Tue, 16 Nov 2010 13:00:49 +0000 (UTC) Received: by qyk7 with SMTP id 7so690937qyk.13 for ; Tue, 16 Nov 2010 05:00:48 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma; h=domainkey-signature:mime-version:received:received:in-reply-to :references:date:message-id:subject:from:to:cc:content-type :content-transfer-encoding; bh=fO31/jLkIpGfOJ+2jYjcpfa+pDyiyV8kvcPIVPiXGMQ=; b=CT5ML39Yww7ZmTZUrNvBdG7U4OXvnh3A4r8eHhad7MlCL45/fQHkjLjBXbAd5uMkxa tbYww+w/NIUIUOasGN+Vv/cYK16EgrNaKhhb2uaUNCbgaNHmaeTw/RsGTaLbgJXQMdea sIeY173NE+GdhTA7On61IVyPjZnfph0xqmg68= 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=GL0Ez9flv895UlyKfzZ4hp69U56Qna9rLh7cKYaZdA1OGOAQTbnD+c2BTWYHsACzFy 8R8rFgP2W1N6lEVz9ahAjO1KSbR0db54o+C5UzRhXNLjre5HSuimtfjnTV0TvPfCIVCV uK3e96/D5zxuSr5BhaBINQBvR/+F2jIHc/yLk= MIME-Version: 1.0 Received: by 10.229.89.202 with SMTP id f10mr6306093qcm.212.1289912448665; Tue, 16 Nov 2010 05:00:48 -0800 (PST) Received: by 10.229.231.81 with HTTP; Tue, 16 Nov 2010 05:00:48 -0800 (PST) In-Reply-To: <20101116135557.66601irt6kd1gndw@webmail.leidinger.net> References: <20101116003029.GC79816@numachi.com> <20101116135557.66601irt6kd1gndw@webmail.leidinger.net> Date: Tue, 16 Nov 2010 14:00:48 +0100 Message-ID: From: Christer Solskogen To: Alexander Leidinger Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable Cc: freebsd-stable@freebsd.org, Ivan Voras Subject: Re: "High" cpu usage when using ZFS cache device X-BeenThere: freebsd-stable@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Production branch of FreeBSD source code List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 16 Nov 2010 13:00:50 -0000 On Tue, Nov 16, 2010 at 1:55 PM, Alexander Leidinger wrote: > How do you measure that nothing is read or written to it? > I used zpool iostat -v > Please check with > =A0gstat -f '^$' > if there are really no reads/writes to the device (please replace > with the name of your USB device, e.g. da0). > > If you see writes, I would say > =A0- this is the reason for the load > =A0- your cache is on the way to be filled with > =A0 useful data > I see almost no writes (nor reads) > If gstat shows zero activity, I suggest to run 'top -S' and look at the > process(es) which consume about 10% CPU (do not take care about the idle > process). Based upon this we can maybe suggest further things to > investigate. > Heres the output of that: CPU: 0.0% user, 0.0% nice, 11.8% system, 0.0% interrupt, 88.1% idle Mem: 841M Active, 193M Inact, 5086M Wired, 4876K Cache, 1237M Buf, 5750M Fr= ee Swap: 8192M Total, 8192M Free PID USERNAME THR PRI NICE SIZE RES STATE C TIME WCPU COMMAN= D 11 root 8 171 ki31 0K 128K CPU0 0 ??? 713.62% idle 5 root 5 -8 - 0K 76K zvol:i 5 401.9H 91.16% zfsker= n Thanks for your time on looking into this :-) --=20 chs,