From owner-freebsd-stable@freebsd.org Wed Jun 20 16:13:42 2018 Return-Path: Delivered-To: freebsd-stable@mailman.ysv.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2610:1c1:1:606c::19:1]) by mailman.ysv.freebsd.org (Postfix) with ESMTP id 4F6941021EFA for ; Wed, 20 Jun 2018 16:13:42 +0000 (UTC) (envelope-from wlosh@bsdimp.com) Received: from mail-io0-x22c.google.com (mail-io0-x22c.google.com [IPv6:2607:f8b0:4001:c06::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 CE8C982C57 for ; Wed, 20 Jun 2018 16:13:41 +0000 (UTC) (envelope-from wlosh@bsdimp.com) Received: by mail-io0-x22c.google.com with SMTP id t6-v6so239496iob.10 for ; Wed, 20 Jun 2018 09:13:41 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=bsdimp-com.20150623.gappssmtp.com; s=20150623; h=mime-version:sender:in-reply-to:references:from:date:message-id :subject:to:cc; bh=6AdGx5ajBHn1yls/qsxrTd0blzTW7PZnujD9oDvx8Ps=; b=TMM0PsjFI7sVYnE2kACiqPQbI2ta0yoE7WgEwYkKwGNStlKba9slleXsg8aNMVS+/8 olXyWws40eld0YNnSbSz2u5Hs1vzSrYa4TfLAlqC4iDeqYFfxHhAcAxHn1+9EpItxUWZ mjncrmkHO/TqFRiChCA4x05pqOfqYP4pypB5NDe16fBF7E+vhvrBQQ7ZsUVMqmHEfX3r tbD6O7TFLvcIPqpwS04gEE19gFe3ukJmvh+qyN8vwjqrx6gQr7ujQ6taCtFMl05Ex8jy 4eqwFxdOZ6E3Vl/EsGKLQSzGp/Em+tO0k6lIp8sbd1lAnkUkSWbWtnDFUcHeX5+uN9d0 QjZg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:sender:in-reply-to:references:from :date:message-id:subject:to:cc; bh=6AdGx5ajBHn1yls/qsxrTd0blzTW7PZnujD9oDvx8Ps=; b=nXDB843EVj3Flpc6uHu6quUzMpzO33Tw+L0Gb2p+EzQR1eoxo6bXz996GIMKM/kw2P 4O7ohiWP7ox6MaeErhgcNZwSsQMRAjQ+G2UzGLOY85OsNaeaFo/fUf0V4mNSBE2soS60 o9dft55yPanc8woXa9ymHsgXJQaH1shhurxFniesb31KmvK5Q+h7y5VdbfqP8F6blFJo inUWlDpCm+WK8eQgd+ABkebsQxWcOP6HTqUnyAlfHO0RVXPvo/aqhhXAcuxtn9afwC/O 9AUHeKHJUh6UOc7s+uwLSDepBSg6z26YTl74gJCT1xjEYEeuK8NZWoa2sVN8GtQgZWkY NUrw== X-Gm-Message-State: APt69E12kJ75eBKiMo6aFOHsYtvI0ltgbW/YNN3eRkDA/Mff8ruIWog1 X/0xumzpyZ6Lg7OssStke6RfjUDj1z3jXnjU3VXkWw== X-Google-Smtp-Source: ADUXVKKPBw2P780F3U5sxesgOu2rWZDhp0g6W3L39jO+iL/QytxP8VnTpfg2Vgrwp8ZucV65CDotN5JPMSxQLVB8FU8= X-Received: by 2002:a6b:29c4:: with SMTP id p187-v6mr17152163iop.299.1529511221035; Wed, 20 Jun 2018 09:13:41 -0700 (PDT) MIME-Version: 1.0 Sender: wlosh@bsdimp.com Received: by 2002:a4f:5945:0:0:0:0:0 with HTTP; Wed, 20 Jun 2018 09:13:40 -0700 (PDT) X-Originating-IP: [50.227.106.226] In-Reply-To: <98c4156c-d2f0-f0c6-b859-9cea8ec29a42@quip.cz> References: <98c4156c-d2f0-f0c6-b859-9cea8ec29a42@quip.cz> From: Warner Losh Date: Wed, 20 Jun 2018 10:13:40 -0600 X-Google-Sender-Auth: qEEqObKqdW54Ov12qqUE1GnNgok Message-ID: Subject: Re: iostat busy value calculation To: Miroslav Lachman <000.fbsd@quip.cz> Cc: FreeBSD-STABLE Mailing List Content-Type: text/plain; charset="UTF-8" X-Content-Filtered-By: Mailman/MimeDel 2.1.26 X-BeenThere: freebsd-stable@freebsd.org X-Mailman-Version: 2.1.26 Precedence: list List-Id: Production branch of FreeBSD source code List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 20 Jun 2018 16:13:42 -0000 On Wed, Jun 20, 2018 at 8:55 AM, Miroslav Lachman <000.fbsd@quip.cz> wrote: > I would like to know how the value of disk "busy" is calculated? > > I want to use values from iostat in the monitoring (zabbix). > iostat shows averages by default and the last column is "busy %", but the > first output contains averages from the system boot til now. > %busy comes from the devstat layer. It's defined as the percent of the time over the polling interval in which at least one transaction was awaiting completion by the lower layers. It's an imperfect measure of how busy the drives are (in ye-olden days, before tagged queuing and NCQ, it was OK because you had THE transaction pending and it was a good measure of how utilized things were. Now with concurrent I/O in flash devices, it's only an imperfect approximation). Warner