From mboxrd@z Thu Jan 1 00:00:00 1970 From: Adam Goryachev Subject: Re: Raid1 to Raid 10 Date: Sat, 09 Feb 2013 01:58:00 +1100 Message-ID: <51151278.20806@websitemanagers.com.au> References: <5115090A.5040908@gmx.net> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <5115090A.5040908@gmx.net> Sender: linux-raid-owner@vger.kernel.org To: Cocolocko Cc: linux-raid@vger.kernel.org List-Id: linux-raid.ids On 09/02/13 01:17, Cocolocko wrote: > is it possible to expand/upgrade a existing Software Raid1 with two > harddisks under CentOS 6.3 to a Raid 10? > I want to put 2 more disks inside to have more speed for Databases and > KVM virtualisation with the Raid0. Personally, I'd do something like this: 1) Physically add the 2 new drives 2) Create a RAID10 array with two missing drives, something like: mdadm --create /dev/md10 --level=raid10 --raid-devices=4 /dev/sdc1 missing /dev/sdd1 missing 3) Unmount, stop using the existing RAID1 4) Copy old RAID1 (md1) to new RAID10 (md10) dd if=/dev/md1 of=/dev/md10 5) Destroy old RAID1 mdadm -S /dev/md1 mdadm --zero-superblock /dev/sda1 mdadm --zero-superblock /dev/sdb1 6) Add the old RAID1 devices to the RAID10 mdadm --manage /dev/md10 --add /dev/sda1 mdadm --manage /dev/md10 --add /dev/sdb1 You should check that all the above command lines are valid/correct, and especially the device names. You might also like to carefully specify the chunk size, as this can impact performance. Finally, you might consider with 4 disks will be enough, you can't grow a RAID10 array (except replace all disks with larger ones) to improve performance, so perhaps you should use 8 smaller disks instead of 4 large disks and try and get faster disks (rpm) to maximise performance. Hope this helps. Regards, Adam -- Adam Goryachev Website Managers Ph: +61 2 8304 0000 adam@websitemanagers.com.au Fax: +61 2 8304 0001 www.websitemanagers.com.au