From mboxrd@z Thu Jan 1 00:00:00 1970 From: Neil Brown Subject: Re: Linux Software RAID Bitmap Question Date: Wed, 28 Feb 2007 08:04:15 +1100 Message-ID: <17892.40143.389564.172608@notabene.brown> References: <17890.24681.249414.635536@notabene.brown> <45E46D7F.9000501@tmr.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: message from Bill Davidsen on Tuesday February 27 Sender: linux-raid-owner@vger.kernel.org To: Bill Davidsen Cc: Justin Piszcz , linux-raid@vger.kernel.org List-Id: linux-raid.ids 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. > > 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. NeilBrown