From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Guy Watkins" Subject: RE: feature suggestion to handle read errors during re-sync of raid5 Date: Mon, 01 Feb 2010 08:33:40 -0500 Message-ID: References: <4B6471A1.2070407@texsoft.it> <4B6482BD.6090102@anonymous.org.uk> <4B65AD05.5050000@anonymous.org.uk> <4B662ED1.3060003@gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Return-path: In-reply-to: Sender: linux-raid-owner@vger.kernel.org To: 'Mikael Abrahamsson' , 'Linux RAID' List-Id: linux-raid.ids I have always read that drives remap on failed write. But have not read anything new in 2+ years. } -----Original Message----- } From: linux-raid-owner@vger.kernel.org [mailto:linux-raid- } owner@vger.kernel.org] On Behalf Of Mikael Abrahamsson } Sent: Monday, February 01, 2010 2:16 AM } To: Linux RAID } Subject: Re: feature suggestion to handle read errors during re-sync of } raid5 } } On Sun, 31 Jan 2010, Roger Heflin wrote: } } > Bit errors seem more likely the longer a sector has set since being } > written. I would be not expect to see errors if you read the entire } > disk, and then reread it 1x a day for a year, but if you read the disk } > once, let it sit spinning for a year without any reads and read it } > again, this will almost certainly get a read error. When you keep } > rereading it, when the bits start to go bad the disk should move it long } > before data loss happens, but if you only read it 1x a year, it is } > likely that when you find the data bad there will be too many bad bits, } > beyond being able to correct it. } } Are you sure that drives today remap like that (if it tries to read it and } only succeeds on the 5th try, it'll reallocate the sector)? } } Looking at "reallocated sectors" on my drives, I've never seen this } happen. That SMART parameter has never increased unless I had a hard UNC } and re-wrote the sector (and a lot of the times, not even that). } } -- } Mikael Abrahamsson email: swmike@swm.pp.se } -- } To unsubscribe from this list: send the line "unsubscribe linux-raid" in } the body of a message to majordomo@vger.kernel.org } More majordomo info at http://vger.kernel.org/majordomo-info.html