From mboxrd@z Thu Jan 1 00:00:00 1970 From: Tomasz Chmielewski Subject: Re: identifying failed disk/s in an array. Date: Wed, 23 Jan 2008 07:56:41 +0100 Message-ID: <4796E529.7030502@wpkg.org> References: <479765CF.A931.0080.0@ems.rmit.edu.au> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <479765CF.A931.0080.0@ems.rmit.edu.au> Sender: linux-raid-owner@vger.kernel.org To: Michael Harris Cc: linux-raid@vger.kernel.org List-Id: linux-raid.ids Michael Harris schrieb: > Hi, > > I have just built a Raid 5 array using mdadm and while it is running fine I have a question, about identifying the order of disks in the array. > > In the pre sata days you would connect your drives as follows: > > Primary Master - HDA > Primary Slave - HDB > Secondary - Master - HDC > Secondary - Slave -HDD > > So if disk HDC failed i would know it was the primary disk on the secondary controller and would replace that drive. > > My current setup is as follows > > MB Primary Master (PATA) Primary Master - Operating System > > The array disks are attached to: > > MB Sata port 1 > MB Sata port 2 > PCI card Sata port 1 > > When i setup the array the OS drive was SDA and the other SDB,SDC,SDD. > > Now the problem is everytime i reboot, the drives are sometimes detected in a different order, now because i mount root via the UUID of the OS disk and the kernel looks at the superblocks of the raided drives everything comes up fine, but I'm worried that if i move the array to another machine and need to do a mdadm --assemble that i won't know the correct order of the disks and what is more worrying if i have a disk fail say HDC for example, i wont know which disk HDC is as it could be any of the 5 disks in the PC. Is there anyway to make it easier to identify which disk is which?. If the drives have any LEDs, the most reliable way would be: dd if=/dev/drive of=/dev/null Then look which LED is the one which blinks the most. -- Tomasz Chmielewski http://wpkg.org