From owner-freebsd-stable@FreeBSD.ORG Wed Jan 27 00:50:02 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 61CB3106566B for ; Wed, 27 Jan 2010 00:50:02 +0000 (UTC) (envelope-from dgerow@afflictions.org) Received: from out2.smtp.messagingengine.com (out2.smtp.messagingengine.com [66.111.4.26]) by mx1.freebsd.org (Postfix) with ESMTP id 313948FC17 for ; Wed, 27 Jan 2010 00:50:01 +0000 (UTC) Received: from compute1.internal (compute1.internal [10.202.2.41]) by gateway1.messagingengine.com (Postfix) with ESMTP id 9DB73CE602; Tue, 26 Jan 2010 19:50:01 -0500 (EST) Received: from heartbeat2.messagingengine.com ([10.202.2.161]) by compute1.internal (MEProxy); Tue, 26 Jan 2010 19:50:01 -0500 DKIM-Signature: v=1; a=rsa-sha1; c=relaxed/relaxed; d=messagingengine.com; h=date:from:to:cc:subject:message-id:references:mime-version:content-type:in-reply-to; s=smtpout; bh=hicX2x0RN8eSC18HD7X88kiH79c=; b=Pgu562btMBvHSXbbnT0GuzS7xcROQgD7XGzgW2IRJTfOUAw/VzaSaGbMAjKABmyf4z0WWL7tFIHFotBDJ+g+sYx4nMt/bi9EY29M7Nea/UUVfwkAj7LpmOADRTkWIvu7F5Go4XCqHh6UeMsy6nxEvNluIAIfjNY8/1xbukY32Hg= X-Sasl-enc: Q746YXBne0movj9Hd4pZW/11AuwklRVomkyocIRKhTQ2 1264553401 Received: from plebeian.afflictions.org (CPE000db917e8b9-CM0019475d4056.cpe.net.cable.rogers.com [174.115.162.77]) by mail.messagingengine.com (Postfix) with ESMTPSA id 69FBEB9B6; Tue, 26 Jan 2010 19:50:01 -0500 (EST) Received: by plebeian.afflictions.org (Postfix, from userid 1001) id 87F68D6; Tue, 26 Jan 2010 19:49:05 -0500 (EST) Date: Tue, 26 Jan 2010 19:49:05 -0500 From: Damian Gerow To: Dan Naumov Message-ID: <20100127004905.GF9206@plebeian.afflictions.org> References: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.20 (2009-06-14) Cc: FreeBSD-STABLE Mailing List Subject: Re: immense delayed write to file system (ZFS and UFS2), performance issues 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: Wed, 27 Jan 2010 00:50:02 -0000 Dan Naumov wrote: : >This drive is sitting, unused, with no filesystem, and I've performed : >approximately zero writes to the disk. : > : >Having a script kick off and write to a disk will help so long as that : >disk is writable; if it's being used as a hot spare in a raidz array, it's : >not going to help much. : : I wouldn't worry in your particular case. A value of 2710 in 508 hours : is a rate of 5,33/hour. At this rate, it's going to take you 56285 : hours or 2345 days to reach 300,000 and most disks will likely : function past 400,000 (over 600,000 all bets are off though). The : people who need(ed) to worry were people like me, who were seeing the : rate increase at a rate of 43+ per hour. Which is why I haven't spoken up on the thread -- I'm not terribly worried. Specific cases aside, writing to the FS is a workaround to a rather inconvenient issue. I, too, would like to see if the problem is fixed, not avoided, by using wdidle -- but I suspect I'll have to contact WD myself to get that confirmation.