From owner-freebsd-questions@FreeBSD.ORG Wed Nov 18 21:54:26 2009 Return-Path: Delivered-To: questions@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 3D59A1065676 for ; Wed, 18 Nov 2009 21:54:26 +0000 (UTC) (envelope-from steve@ibctech.ca) Received: from smtp.ibctech.ca (v6.ibctech.ca [IPv6:2607:f118::b6]) by mx1.freebsd.org (Postfix) with SMTP id 9F5E68FC18 for ; Wed, 18 Nov 2009 21:54:25 +0000 (UTC) Received: (qmail 89121 invoked by uid 89); 18 Nov 2009 21:58:49 -0000 Received: from unknown (HELO ?IPv6:2607:f118::5?) (steve@ibctech.ca@2607:f118::5) by 2607:f118::b6 with ESMTPA; 18 Nov 2009 21:58:49 -0000 Message-ID: <4B046D14.1070505@ibctech.ca> Date: Wed, 18 Nov 2009 16:54:28 -0500 From: Steve Bertrand User-Agent: Thunderbird 2.0.0.17 (Windows/20080914) MIME-Version: 1.0 To: Nerius Landys References: <560f92640911181259m37d2659w775fa3fafd9499b6@mail.gmail.com> In-Reply-To: <560f92640911181259m37d2659w775fa3fafd9499b6@mail.gmail.com> X-Enigmail-Version: 0.96.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Cc: questions@freebsd.org Subject: Re: Measuring disk I/O X-BeenThere: freebsd-questions@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: User questions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 18 Nov 2009 21:54:26 -0000 Nerius Landys wrote: > A friend and I are working on a small video-game related project as a > hobby. We're running several scripts 24/7 that make lots of calls to > a MySQL database. The mysql server process shows an average CPU use > of 1% (reported by top) and it never goes above about 2% The tables > it's hitting are myisam tables. I'm a little bit worried that the > mysql process is using a lot of disk access. I don't know too much > about hard disks but my feeling is that too much disk use could slow > the machine down or cause a premature hard disk failure. WD Raptor > model. > > I don't know if my concerns are well-founded, but I would like to > measure impact on the hard disk somehow. I don't know how to see disk > I/O. I do know how to use top. How do I measure disk I/O? Any other > thoughts? Perhaps gstat(8) will help you get started: # gstat -a dT: 1.001s w: 1.000s L(q) ops/s r/s kBps ms/r w/s kBps ms/w %busy Name 4 176 114 10261 14.9 62 607 25.4 96.8| ar0 4 177 115 10389 17.8 62 607 26.5 100.0| ar0.eli 1 34 34 527 30.8 0 0 0.0 99.1| ar0.elie 2 66 4 16 20.5 62 607 26.6 98.0| ar0.elif 1 77 77 9845 12.1 0 0 0.0 93.0| ar0.elig ...or on ZFS: # zpool iostat 1 capacity operations bandwidth pool used avail read write read write ---------- ----- ----- ----- ----- ----- ----- storage 1.39T 440G 0 771 0 96.4M storage 1.39T 440G 0 1.05K 4.42K 126M Steve