From mboxrd@z Thu Jan 1 00:00:00 1970 From: Richard Scobie Subject: Re: feature suggestion to handle read errors during re-sync of raid5 Date: Tue, 02 Feb 2010 09:30:07 +1300 Message-ID: <4B6739CF.8050808@sauce.co.nz> References: <4B6471A1.2070407@texsoft.it> <4B6482BD.6090102@anonymous.org.uk> <4B65AD05.5050000@anonymous.org.uk> <4B662ED1.3060003@gmail.com> <87r5p556na.fsf@frosties.localdomain> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: Sender: linux-raid-owner@vger.kernel.org To: Mikael Abrahamsson Cc: 'Linux RAID' List-Id: linux-raid.ids Mikael Abrahamsson wrote: > Since the drive has ECC, it would be interesting to see the amount of > read errors ECC has corrected. Would also be interesting to know if the > drive will rewrite a sector if it's ECC corrected, so that ECC doesn't > have to kick in next time (or if they're actually operating in so narrow > margins that they actually use the ECC constantly because the s/n ratio > is bad and that this is part of the design). I guess this is manufacturer and model specific, but looking smartd output from a representative (as in similar errors etc to others of the same model) Seagate SCSI drive, they are not rewriting on ECC: Error counter log: Errors Corrected by Total Correction Gigabytes Total EEC rereads/ errors algorithm processed uncorrected fast | delayed rewrites corrected invocations [10^9 bytes] errors read: 2205106 0 0 2205106 2205106 18342.407 0 write: 0 0 0 0 0 3831.185 0 Regards, Richard