Take the 2-minute tour ×
Super User is a question and answer site for computer enthusiasts and power users. It's 100% free, no registration required.

I have two data disks that were, heretofore, in a mobo RAID configuration in Windows 7 (Ultimate, 64 bit). They are now separate AHCI disks, visible in Computer Management. How to I go about making them a single mirrored volume in Windows?

Note: The data is backed up up on two other separate disks, but it's a fair amount of work to do a restore (over 120'000 files, and I have to reset permissions).

Note2: Currently the two disks are identical, and I can use the content of either one for this.

Edit 1

I've converted one volume to dynamic and deleted the other, and rebooted just in case, but "Add Mirror" is still disabled. Also, trying to create a "New Mirrored Volume" only offers the unallocated disk to include in the mirror.

alt text

Edit 2

The problem seems to be that, although the two disks are identical, the disk to be mirrored needs to be smaller than the disk to which you want to mirror. So I just decreased the partition size by 50 MB and then Add Mirror was available and I was able to mirror (in my screen shot) Disk 3 to Disk 0. I suspect that I needed only a much smaller difference, perhaps 1-10 MB, but it's not worth my time to experiment to find the smallest difference that will mirror.

alt text

Edit 3 (2014-03-31)

Although making the existing disk smaller fixed the problem originally, having subsequently needed to re-mirror the disk at a later date, I then resized the disk back to it's full size and was able to successfully add the mirror - with identical hardware as when this question was posed. So it seems like a bug or quirk in Windows which may have been resolved.

share|improve this question
add comment

1 Answer

up vote 5 down vote accepted

Windows 7 Pro and above.

For new Arrays:

Open up Computer Management, Disk Management. Right-click the unallocated drive and select "New Mirrored Volume"

Select the drives you want to use and edit the volume sizes if necessary. Click Next. You will be prompted to convert the disk to Dynamic disk. Select Yes to continue.

Edit

To mirror an existing drive:

Right click on the original partition -> Add Mirror; the designated mirror must be larger in size.

share|improve this answer
    
This only offers the disk which I deleted to be included in the new array. And the remaining disk does has it's "Add Mirror" option grayed out. –  Lawrence Dol Dec 23 '10 at 16:47
    
See my edit - I can't add the unallocated volume. On the disk with data the Add Mirror is grey, and on the other New Mirrored Volume only presents the unallocated volume for the mirror. –  Lawrence Dol Dec 23 '10 at 17:17
    
The problem seems to be that, although the two disks were identical, the disk to be mirrored needs to be smaller than the disk on which you are mirroring. So I just decreased the partition size by 50 MB and then Add Mirror was available. –  Lawrence Dol Dec 23 '10 at 17:34
    
If you would like to edit your answer to indicate using "Add Mirror" on the allocated disk, instead of "New Mirrored Volume" on the unallocated disk, I would be happy to accept it. –  Lawrence Dol Dec 23 '10 at 17:35
    
@ Software Monkey That's what I call collaborative :-) Glad that I could at least point you in the right direction! –  Weltenwanderer Dec 23 '10 at 20:30
show 1 more comment

Your Answer

 
discard

By posting your answer, you agree to the privacy policy and terms of service.

Not the answer you're looking for? Browse other questions tagged or ask your own question.