Enable RAID on the boot disk without a reinstall

Oct 18, '04 09:38:00AM

Contributed by: Anonymous

When I went to set up RAID on the boot disk on my Mac OS X box, I had trouble finding info on the net about how to do it without having to re-install the OS. Well, here is a step by step account of how I was able to accomplish this.

Read the rest of the article for the how-to -- and please read the dislcaimer before you start doing something like this to your system! These instructions also assume some Terminal knowledge...]

DISCLAIMER: I take no responsibility if you choose to follow the steps below. I make no garauntees that this will work for you, however it did work beautifully for me. You may potentially lose all of your data, so I strongly suggest making a backup copy before trying this!
  1. Install a new hard drive
  2. Boot off Mac OS X Install CD #1
  3. Install a minimal OS on the new hard disk:
  4. Reboot and hold the Option key to get the boot loader menu
  5. Boot off the new hard disk
  6. Open a terminal and su to root
  7. Run the following command: diskutil list:
  8. Next run diskutil enableRAID mirror disk1:
  9. At this point, I reboot the system and hold down Option while it reboots
  10. Now select the old disk to boot from
  11. Log in and open the Disk Utility app in Applications -> Utilities
  12. Select the RAID volume and the RAID tab
  13. Drag the new disk to the RAID
  14. Click Rebuild:
  15. Drink a beer as you now have a mirrored boot drive
There should be an easier way to do this. You could theoretically boot into single user mode off of the Install CD, and bypass installing the OS on the new drive. However, diskutil seems to be broken in single user mode; I believe this is a known bug.

Comments (13)


Mac OS X Hints
http://hints.macworld.com/article.php?story=20041013121106176