From mboxrd@z Thu Jan 1 00:00:00 1970 From: Bill Davidsen Subject: Re: Linux Software RAID Bitmap Question Date: Tue, 27 Feb 2007 22:00:32 -0500 Message-ID: <45E4F050.2090109@tmr.com> References: <17890.24681.249414.635536@notabene.brown> <45E46D7F.9000501@tmr.com> <17892.40143.389564.172608@notabene.brown> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <17892.40143.389564.172608@notabene.brown> Sender: linux-raid-owner@vger.kernel.org To: Neil Brown Cc: Justin Piszcz , linux-raid@vger.kernel.org List-Id: linux-raid.ids Neil Brown wrote: > On Tuesday February 27, davidsen@tmr.com wrote: > >> Neil Brown wrote: >> >>> When md find a bad block (read failure) it either fixes it (by >>> successfully over-writing the correct date) or fails the drive. >>> >>> The count of the times that this has happened is available via >>> /sys/block/mdX/md/errors >>> >>> >> What kernel provides this? I have system running everything from 2.6.15 >> to 2.6.20-get14, and there is no such file in any of them. There is a >> per-device errors file one level down, but that presumably wouldn't be >> in the superblock. >> > > Sorry, I did get that wrong. As you say it is a per-device field: > /sys/block/mdX/md/dev-*/errors > > which makes sense because it is individual devices that get errors, > not whole arrays. And it *is* stored in the superblock for v1. The > superblock has a per-device section which is potentially different on > each device, The corrected-error count is stored there. > > OK, I can add... >> Do I have to go from 0.90 to v1 or later superblocks to get this, and if >> so is that a safe thing to do? >> > > It is not currently easy to convert a v0.90 array to use v1 > superblocks. I should put that on my todo list as it isn't > conceptually hard. Unfortunately the thing I'd like most is hard (RAID5E), but if/when the SB conversion is available I would give it a test drive. -- bill davidsen CTO TMR Associates, Inc Doing interesting things with small computers since 1979