From mboxrd@z Thu Jan 1 00:00:00 1970 From: Josh Reynolds Subject: RAID10 only using 2/4 drives Date: Wed, 11 Jan 2012 08:51:34 -0600 Message-ID: <4F0DA1F6.9070700@yagermaterials.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 Hello! 1st post on this mailing list, so be gentle. I've got a production Ubuntu box that I used the installer to create a raid10 system on several months ago. I pretty much setup the box and then left it alone, to run a couple of different things and some vm's. I really started to realize something was wrong fairly recently when my disk size was showing approx 1/2 of what I thought it should for a raid10. Also, my disk speeds were... not something I'd expect for 4 drives. After looking into it, I realized mdadm had marked two of the drives as spares. WTF. To make sure that I wasn't crazy, I wiped out a partition on each drive, and created a raid10 by hand. My original system array is md0, the other is md1. ---------------------------- josh@virtserver:~$ cat /proc/mdstat Personalities : [raid0] [raid1] [raid10] md1 : active raid10 sda2[0] sdd2[3] sdc2[2] sdb2[1] 46868480 blocks super 1.2 512K chunks 2 far-copies [4/4] [UUUU] md0 : active raid10 sdd3[4](S) sdb3[3](S) sdc3[2] sda3[0] 951370752 blocks super 1.2 512K chunks 2 far-copies [2/2] [UU] bitmap: 3/8 pages [12KB], 65536KB chunk --------------------------- I notice the 2nd array I created is showing the raid1 and raid0 personalities... and I have a feeling that's what is gimping the md0 array? I've tried fail/remove/adding those two partitions marked as spares, and it never adds them back as active members. HELP! :) - Josh