From owner-freebsd-questions@FreeBSD.ORG Mon Oct 19 23:34:24 2009 Return-Path: Delivered-To: freebsd-questions@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 8DC65106566B for ; Mon, 19 Oct 2009 23:34:24 +0000 (UTC) (envelope-from carl@chave.us) Received: from mail-gx0-f218.google.com (mail-gx0-f218.google.com [209.85.217.218]) by mx1.freebsd.org (Postfix) with ESMTP id 57D6F8FC12 for ; Mon, 19 Oct 2009 23:34:23 +0000 (UTC) Received: by gxk10 with SMTP id 10so4573526gxk.3 for ; Mon, 19 Oct 2009 16:34:23 -0700 (PDT) MIME-Version: 1.0 Received: by 10.101.194.8 with SMTP id w8mr775917anp.190.1255995263262; Mon, 19 Oct 2009 16:34:23 -0700 (PDT) In-Reply-To: <4ADC5318.2010706@cam.ac.uk> References: <4ADC5318.2010706@cam.ac.uk> Date: Mon, 19 Oct 2009 19:34:23 -0400 Message-ID: From: Carl Chave To: Christopher Key Content-Type: text/plain; charset=ISO-8859-1 Cc: freebsd-questions@freebsd.org Subject: Re: ZFS: Strange performance issues 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: Mon, 19 Oct 2009 23:34:24 -0000 Chris, Don't know, but, I will paste in a portion of the ZFS admin guide from SUN: Because these statistics are cumulative since boot, bandwidth might appear low if the pool is relatively idle. You can request a more accurate view of current bandwidth usage by specifying an interval. For example: # zpool iostat tank 2 Later it says about the -v option: You can use the same set of options (interval and count) when examining virtual device statistics. http://dlc.sun.com/pdf/819-5461/819-5461.pdf Page 95