Windows 10: Disk mirror failed redundancy: Remove mirror or reactivate volume?

Situation:

Windows 10 1803 computer. OS drive is fine. Have two other very large disks ("3" and "4"), mirrored from within Windows. "4" has problem, taking it offline and losing its data (now shows up as "Missing").


Currently we're able to read data from disk #3. Disk Management shows the two disks from the original mirror, both with failed redundancy:





If I right-click on either of them, several options are presented...


"Break Mirrored Volume..." is greyed out, so can't do that.

"Remove Mirror..." is available.

"Reactivate Volume" is available.


Since only disk 3 actually has data on it, we want to preserve it. However, there is too much data for us to backup reasonably; whatever solution we try must not destroy that information.


If we selected "Remove Mirror..." we get this dialogue box:





In our opinion, the text in the dialogue box is not clear. If we run the "Remove Mirror," which drive do we select in order to retain our data? Is the selected drive the one which has its data gone (removed, deleted, toast), OR is that the drive which has its mirrored data removed (which would be the other drive?


Or... maybe we select "Reactivate Volume"? Does that reactivate the mirrored volume or the specific disk which is selected when reactivation is selected? (as in drive "3" or "Missing"). How do we know which drive's data is considered the "good" data, which will be mirrored to the other drive? Would be bad to have the non-data from the "Missing" drive to be copied over the real data on drive "3."


Have done a bunch of searching, but haven't found adequate answers.

:)

 

Disk mirror failed redundancy: Remove mirror or reactivate volume?

Hi,



Thank you for writing to Microsoft Community Forums.



The cause for Failed Redundancy would be that half, but not both halves, of a mirrored volume was imported. In Disk Management, the imported half of the mirrored volume receives Failed Redundancy status, while the disk that holds the
half of the mirror that was not imported receives Missing status. You can import the Missing disk at a later time to restore redundancy.



The solution for Failed Redundancy is to move all disks that span this volume to the new computer at the same time, and then import all of the disks together.



The complete solution is giving in the section A mirrored volume's status is Data Not Redundant from
Troubleshooting Disk Management.



You may also refer the section A dynamic disk's status is Offline or Missing from the above article and try the troubleshooting steps.



If you are still facing any issues related to Mirroring, then I suggest you to post your query in
IT Pro TechNet forums, where we have support professionals who are well equipped with the knowledge on Hard Disk Mirroring.



Hope it helps.



Let us know if you got the help you needed by clicking Yes or No.

 

Disk mirror failed redundancy: Remove mirror or reactivate volume?

Situation:

Windows 10 1803 computer. OS drive is fine. Have two other very large disks ("3" and "4"), mirrored from within Windows. "4" has problem, taking it offline and losing its data (now shows up as "Missing").

Currently we're able to read data from disk #3. Disk Management shows the two disks from the original mirror, both with failed redundancy:





If I right-click on either of them, several options are presented...

"Break Mirrored Volume..." is greyed out, so can't do that.

"Remove Mirror..." is available.

"Reactivate Volume" is available.

Since only disk 3 actually has data on it, we want to preserve it. However, there is too much data for us to backup reasonably; whatever solution we try must not destroy that information.

If we selected "Remove Mirror..." we get this dialogue box:





In our opinion, the text in the dialogue box is not clear. If we run the "Remove Mirror," which drive do we select in order to retain our data? Is the selected drive the one which has its data gone (removed, deleted, toast), OR is that the drive which
has its mirrored data removed (which would be the other drive?

Or... maybe we select "Reactivate Volume"? Does that reactivate the mirrored volume or the specific disk which is selected when reactivation is selected? (as in drive "3" or "Missing"). How do we know which drive's data is considered
the "good" data, which will be mirrored to the other drive? Would be bad to have the non-data from the "Missing" drive to be copied over the real data on drive "3."

Have done a bunch of searching, but haven't found adequate answers.

 

Windows 10 pro mirrored disks - 'Failed Redundancy'

hi everyone, I am hoping someone can help me with this. I have four 3 TB hard disk drives on my PC making up two 3 TB mirrored volumes. One of these volumes is showing 'Failed Redundancy'. I have verified that all four hard disks can be seen in the device
manager so it didn't initially appear that one of the disks has failed. Furthermore, in disk manager all of the hard disks are showing as online.

What can I do to troubleshoot and resolve this problem?

Many thanks