From mboxrd@z Thu Jan 1 00:00:00 1970 From: Brendan Conoboy Subject: Re: replace disk in raid5 without linux noticing? Date: Wed, 19 Apr 2006 10:41:40 -0700 Message-ID: <44467654.2060903@swcp.com> References: <200604191631.04305.Dexter.Filmore@gmx.de> <1145466223.8608.84.camel@localhost.localdomain> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <1145466223.8608.84.camel@localhost.localdomain> Sender: linux-raid-owner@vger.kernel.org To: mingz@ele.uri.edu Cc: Shai , Dexter Filmore , linux-raid@vger.kernel.org List-Id: linux-raid.ids Ming Zhang wrote: >> Why can't you just mark that drive as failed, remove it and hotadd a >> new drive to replace the failed drive? > > because background rebuild is slower than disk to disk copy, since his > disk is still fully functional. Wouldn't it be great if every disk in a RAID volume were in its own way a degraded RAID1 device without a mirror? Then when any drive started generating recoverable errors and warnings a mirror could be allocated without any downtime. You can certainly generate a layout like this manually, but it would be nice to have that sort of feature out of the box (and without the performance hit!). This would help a great deal in a situation such as Dexter's. -Brendan (synk@swcp.com)