From mboxrd@z Thu Jan 1 00:00:00 1970 From: Reindl Harald Subject: Re: Disk Monitoring Date: Thu, 29 Jun 2017 12:10:28 +0200 Message-ID: <38899f11-c6d2-cab7-eb25-093cfa802b40@thelounge.net> References: <20170628131917.BF1911235B6@gemini.denx.de> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: Content-Language: de-CH Sender: linux-raid-owner@vger.kernel.org To: Gandalf Corvotempesta , Wolfgang Denk Cc: linux-raid@vger.kernel.org List-Id: linux-raid.ids Am 29.06.2017 um 11:52 schrieb Gandalf Corvotempesta: > Linux kernels detect something bad only by accessing to the failed > sector. If that sector is not used, > kernel knows nothing. HW RAID like LSI are able to read the whole > disks, block by block, even the unused part, > detecting failures before something is trying to write to that sector > > If you have a bad sector on an unused part of the array, when you have > to rebuild due to another disk failure, you'll > hit a URE and the whole array is failed there is nothing like "unused part of the array" since the linux-raid-layer knows nothing about the filesystem on top and hence a raid-check (scrub) reads every block as said hardware controller