From mboxrd@z Thu Jan 1 00:00:00 1970 From: Ruslan Sivak Subject: Re: raid10 on centos 5 Date: Fri, 04 May 2007 19:21:35 -0400 Message-ID: <463BBFFF.70000@istandfor.com> References: <200705042313.l44NDL712377@www.watkins-home.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <200705042313.l44NDL712377@www.watkins-home.com> Sender: linux-raid-owner@vger.kernel.org To: Guy Watkins Cc: linux-raid@vger.kernel.org List-Id: linux-raid.ids Guy Watkins wrote: > } -----Original Message----- > } From: linux-raid-owner@vger.kernel.org [mailto:linux-raid- > } owner@vger.kernel.org] On Behalf Of Ruslan Sivak > } Sent: Friday, May 04, 2007 12:22 PM > } To: linux-raid@vger.kernel.org > } Subject: raid10 on centos 5 > } > } I am trying to set up raid 10 and so far with no luck. I have 4 drives, > } and Anaconda will not let me do raid 10. mdadm doesn't have the raid 10 > } personality loaded. When I create the array manually like so: > } > } 2 drives in /dev/md11 as raid1 > } 2 drives in /dev/md12 as raid1 > } md11 and md12 in /dev/md10 as raid0 > } > } Everything looks fine from the shell, but anaconda only sees md11 and > } md12. > } > } The only choice I see is to set up LVM over md11 and md12. Is this > } really raid10? > } > } Russ > > You are making a RAID1+RAID0 array. > Try making a real RAID10 array with 4 drives. This way you would only have > 1 array with 4 drives. > > >From the mdadm man page: > Currently, Linux supports LINEAR md devices, RAID0 (striping), RAID1 > (mirroring), RAID4, RAID5, RAID6, RAID10, MULTIPATH, and FAULTY. > > Notice RAID10 is listed, use that. Man mdadm for more info. > > However, I would (and do) use RAID6. With RAID6 any 2 disks can fail > without data loss. With RAID1+RAID0, any one disk can fail, a second > failure has a 1 in 3 chance of vast data loss. > > I hope this helps, > Guy > > - > Guy, That's what I've been trying to do. Unfortunatelly, my distro, CentOS 5 (based on RHEL 5, I believe), does not have the RAID10 personality in the kernel. I guess I would have to compile my own kernel and load the module through a driver disk. Would that work? Are there some instructions somewhere I can follow? Russ