From mboxrd@z Thu Jan 1 00:00:00 1970 From: hpa@zytor.com (H. Peter Anvin) Subject: Re: Good news / bad news - The joys of RAID Date: Thu, 9 Dec 2004 00:17:12 +0000 (UTC) Message-ID: References: <200412021147.12410.systemloc@earthlink.net> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7BIT Return-path: Sender: linux-raid-owner@vger.kernel.org To: linux-raid@vger.kernel.org List-Id: linux-raid.ids Followup to: <200412021147.12410.systemloc@earthlink.net> By author: TJ In newsgroup: linux.dev.raid > > I do not think the deathstar incident was due to a firmware problem as you > describe at all. I had a lot of these drives fail, and I read as much as I > could find on the subject. The problem was most likely caused by the fact > that these drives used IBM's new glass substrate technology. This substrate > had heat expansion issues which caused the heads to misalign on tracks and > eventually cross write over tracks, corrupting data. The classic "click of > death" was the sound of the drive searching for a track repetitively. In some > cases a format would allow the drive to be used again, in many cases it would > not. It is my belief that formatting was inneffective at fixing the drive > because the cross writing probably hit some of the low level data, which the > drive cannot repair on a format. > It's also worth noting that there was extremely high correlation between which factory built the drives and the failure rates. Apparently some factories had virtually zero instances of this problem. -hpa