From mboxrd@z Thu Jan 1 00:00:00 1970 From: Piergiorgio Sartor Subject: Re: Suggestion for hot-replace Date: Sun, 25 Nov 2012 16:42:57 +0100 Message-ID: <20121125154257.GA4565@lazy.lzy> References: <10107277.2.1353857505404.JavaMail.root@zimbra> <4164037.TSORKSTxib@workstation-home> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: <4164037.TSORKSTxib@workstation-home> Sender: linux-raid-owner@vger.kernel.org To: Tommy Apel Hansen Cc: Roy Sigurd Karlsbakk , Linux RAID Mailing List List-Id: linux-raid.ids On Sun, Nov 25, 2012 at 04:36:34PM +0100, Tommy Apel Hansen wrote: > On Sunday 25 November 2012 16:31:45 Roy Sigurd Karlsbakk wrote: > > > Hello, personally I would vote for an option to rotate spares into and > > > array > > > like Peter suggests, keeping a drive idle doesn't guarrantee that it's > > > actually operational. > > > > Only problem with this, is if you do it frequently, it'll degrade > > performance. > > > > Btw, is there a way to replace a drive without failing one? In RAID-5, a > > common issue is to have a failed drive and then find bad sectors on > > another. In this setting (and possibly others), it'd be good to have md > > replace the drive while still active (like what can be done in ZFS). > > Well both options serve a purpose, but say you rotate a spare into the array > that then fails on spinup, then you would have a faulted array as your > implementation plan states that a drive cannot be "older" than x hours, then > you would have and endless loop where as the other option would suggest to > zero the former drive and reinstate it. I do not know if you answered to my message, anyhow the spare can fail in any case, idle or not. This is a situation the system should be able to couple with, for example testing the spare before starting the hot replace operation. Which is good in any case. bye, -- piergiorgio