From mboxrd@z Thu Jan 1 00:00:00 1970 From: Bill Cizek Subject: Adding a device to an active RAID1 array Date: Wed, 18 Jan 2006 12:58:36 -0600 Message-ID: <43CE8FDC.4020501@rcn.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Return-path: Sender: linux-raid-owner@vger.kernel.org To: linux-raid@vger.kernel.org List-Id: linux-raid.ids Hi, Are there any known issues with changing the number of active devices in a RAID1 array? I'm trying to add a third mirror to an existing RAID1 array of two disks. I have /dev/md5 as a mirrored pair of two 40 GB disks. Directly on top of it is a 40 GB XFS filesystem. When I do "mdadm --grow /dev/md5 -n 3" the count of devices changes from 2 to 3, as expected. If the XFS filesystem is mounted, the array size changes to 3.0 GB. If it is not mounted everything works fine. Is this supposed to work, is it required that the array be inactive to add a disk, or am I just doing something stupid? If there is a better forum for this question, please direct me there. In any case TIA for any help. -Bill