Create a RAID 1 Array with an Existing Drive

So, last month the IT department at DIRC was made redundant due to funding issues (The joys of working for the not-for-profit sector), as a result myself and colleague David were out of a job. If you’re looking for a new media consultant, Dave’s your man.

Luckily, after a weeks vacation and procrastinating about updating my resume / beginning to find a new source of income to cover my rent, I was offered a new job at – Cheap Cigarettes made in Australia. The work’s completely different, so it’s a great new learning curve, and hopefully the addictive qualities of nicatine should keep me in a job! 😉

I’ve got a new HP DL585 server that I’m using for development, and let me say, this thing is a beast. I set it up about 2 weeks ago with Fedora Core 10, but the problem was all our hard drives didn’t arrive with the server, and I needed to get it up and running. I needed to create a RAID 1 mirror of the 36GB 15k SAS system drive but only had 1 of the drives.

This morning, the second drive arrived and I had to figure out how to create a mirror of the existing drive, without having to reinstall the entire OS again or lose any data. Thanks to the power of the command line it made light work of a seemingly daunting problem.


First, create an image of your drive onto another temporary drive:
Mount a partition to store the backup image of the system drive, in this case I used /dev/cciss/c0d1p1

mkdir /media/backup
mount -t ext3 /dev/cciss/c0d1p1 /media/backup

Create an image of the drive you’re wanting to use for the RAID array (/dev/cciss/c0d0)

dd bs=4k if=/dev/cciss/c0d0 of=/media/backup/backup.img conv=noerror,sync

Secondly, install the new drive being used as the mirror and create the RAID 1 array using the controller.

Finally, reboot with the Fedora CD in the drive and enter recovery mode. Just skip past any menus that come up until you’re presented with a command prompt.
Now mount the partition with the backup image

mkdir /mnt/backup
mount -t ext3 /dev/cciss/c0d1p1 /mnt/backup

Restore the system drive

dd bs=4k if=/mnt/backup/backup.img of=/dev/cciss/c0d0


Once complete, take the Fedora CD out of the drive and reboot, and the system should be like you never touched it.

This new job has me doing 12 hour days when including travel to and from, so I’ve barely had time to myself. When I get a few days off, I’ll try and get a new update on Flickr Manager pushed out.

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4 Responses to Create a RAID 1 Array with an Existing Drive

  1. Wes Allmond says:

    please make a new version of Flickr manager! It’s the best Flickr plugin out there but it no longer works with the current version of WordPress

  2. Oscar says:

    Pretty nice, that’s a good approach. I think I would have done something very similar if I had to do this. Of course, having had the 2 drives at the same time would have been ideal, but such is the work we get huh.

  3. Tim says:

    I’m totally new to raid. So what your sayin is I can’t just raid 1 my system disc I have to do a special dance.
    My previous computer was a slot1 1gig 1gig memory 440BX gamer board that still won’t die, it now belongs to my 6 and 7 yr olds. What I’m getting at is I’ve got a pretty steep learning curve. If I gather correctly I would have to clone my system drive somewhere else then raid 1 my intended system drives. Then restore my system from the clone. Is that correct?

  4. Yes, that’s correct. I believe *a few* RAID controllers have a smart functionality that will clone and create the array, however that accusation may be completely false.

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