5 Replies Latest reply on May 12, 2010 7:54 AM by randombone

    Breaking RAID 1 while retaining the disk's data

    randombone

      I had a workstation running raid 1 and the raid config is no longer needed. Ideally I'd like to 'turn off' the raid, and use just one of the two disks, keeping intact the OS and the applications. I read here that it's not really possible to just 'turn off' the raid. I experimented enought to see that the two raid software options that would effectively delete or reset the raid would kill all data on those disks. I read somewhere else that a possible solution might be to use a disk cloning software like ghost or driveimage xml to copy the data from one of the raid disks to a newly formatted disk, and then remove the raid disk and boot from the cloned disk.

       

      Of course I'm not sure that'd even work but I am attempting it. So here is what I did.

       

      1. Removed one of the raid drives
      2. After booting the degraded raid, mounted the 'separated' hdd an external hard disk enclosure
      3. Deleted the partitions on the 'separated' hdd.
      4. Recreated the partitions on the 'separated' hdd
      5. Used driveimage xml to copy the data from the remaining raid disk to the 'separated' hdd
      6. Removed the remaining raid disk and installed the cloned disk

       

      Now,that may be the fastrack to nowhere, but what I wanted to be able to do now was to boot from that cloned drive, which I hope can now be booted as a non-raid disk. But of course when I boot the pc, the raid infrastructure is still engaged. I could go into the raid config and chose to delete or reset; but I'd guess that doing that would kill the cloned drive I just created. Or would it?

       

      Hopefully someone here knows enough about how all of this works to give me a path forward. Thanks.

        • 1. Re: Breaking RAID 1 while retaining the disk's data
          PeterUK

          Being a RAID 1 and not a RAID 0 you could just take the drive out and your OS a data is safe and will run like a single drive the problem will be to add a HDD without the raid rebuilding on it which shouldn't happen if you reformat drive and have data on it.

          • 2. Re: Breaking RAID 1 while retaining the disk's data
            randombone

            I'm not sure I understood you. I know I can remove one of the raid disks and the remaining one will keep it's data - it'd just be in a degraded state. But I figured that wasn't ideal...and so somehow wanted to get back to no raid at all. Is the strategy I outlined above going to make that goal possible or not? With some adjustmen, of course.

             

            I for sure didn't understand the last part of what you wrote re the problem being adding a hdd without raid?

            • 3. Re: Breaking RAID 1 while retaining the disk's data
              randombone

              Encouraged by this post (http://communities.intel.com/message/13312#13312) which has some reports of resetting raid 1 without losing data, with the 'clone' hdd installed, reset the raid and set the ami bios to configure sata as ide. The drive now appears as a sata drive in the bios and is listed #2 in the list of boot devices. However, after rebooting the system still reports that there is no boot device.

               

              Is that a by product of the cloning process with which this disk was created? Can I make the disk bootable? Or should I turn on raid again in the bios and raid config screen, put back the remaining raid member, and undo the raid settings again?

              • 4. Re: Breaking RAID 1 while retaining the disk's data
                randombone

                I just tried booting from the ex-raid disk and it seems that it's bootable, intact, and no longer thinks of itself as part of a raid array.

                 

                So it seems likely that if I'd simply reset the raid, I'd have been able to boot from either independent disk? And the reason my attempt earlier today was that somehow the cloned hdd was not bootable.

                 

                I'd really appreciate any input on these question:

                 

                1. Why wasn't the cloned disk bootable? Could it have been made bootable?
                2. What are the exact steps to un-raid a raid 1 set? Is the correct order to reset raid in the raid config screen, then reboot and in the ami bios change IDE Configuration to Configure SATA as IDE? Or the other way around?
                • 5. Re: Breaking RAID 1 while retaining the disk's data
                  randombone

                  I'd sure appreciate it if someone with more experience would provide some input on the questions I posed above, even though my specific situation is resolved.