From owner-freebsd-stable@FreeBSD.ORG Tue Jan 26 19:23:58 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 586411065679 for ; Tue, 26 Jan 2010 19:23:58 +0000 (UTC) (envelope-from cswiger@mac.com) Received: from asmtpout029.mac.com (asmtpout029.mac.com [17.148.16.104]) by mx1.freebsd.org (Postfix) with ESMTP id 12D658FC1B for ; Tue, 26 Jan 2010 19:23:57 +0000 (UTC) MIME-version: 1.0 Content-transfer-encoding: 7BIT Content-type: text/plain; charset=us-ascii Received: from cswiger1.apple.com ([17.209.4.71]) by asmtp029.mac.com (Sun Java(tm) System Messaging Server 6.3-8.01 (built Dec 16 2008; 32bit)) with ESMTPSA id <0KWV007KDCJW8S10@asmtp029.mac.com> for freebsd-stable@freebsd.org; Tue, 26 Jan 2010 11:23:57 -0800 (PST) X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 spamscore=0 ipscore=0 phishscore=0 bulkscore=0 adultscore=0 classifier=spam adjust=0 reason=mlx engine=5.0.0-0908210000 definitions=main-1001260147 From: Chuck Swiger In-reply-to: Date: Tue, 26 Jan 2010 11:23:56 -0800 Message-id: <087264FA-3E22-4855-BC38-346ADF22F422@mac.com> References: To: Dan Naumov X-Mailer: Apple Mail (2.1077) 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: Tue, 26 Jan 2010 19:23:58 -0000 Hi-- On Jan 26, 2010, at 10:45 AM, Dan Naumov wrote: > 9 Power_On_Hours 0x0032 100 100 000 Old_age > Always - 136 > 193 Load_Cycle_Count 0x0032 199 199 000 Old_age > Always - 5908 > > The disks are of exact same model and look to be same firmware. Should > I be worried that the newer disk has, in 136 hours reached a higher > Load Cycle count twice as big as on the disk thats 5253 hours old? Yes. Drive actuators are (or used to be) typically rated for at least 50,000 load-cycle counts; at ~1000 events per day, there's about a 50% chance of such a drive dying before two years are up: http://en.wikipedia.org/wiki/Hard_disk_drive#Landing_zones_and_load.2Funload_technology Some models of drives intended for laptops (typically smaller 2.5" form factor w/ single platter) can tolerate many more load-cycles, and newer drives also claim to handle more. Regards, -- -Chuck