Redundancy failed error RRS feed

  • Question

  • My (Win10) system volume is mirrored, using the system software.
    This morning, in the disk-management applet, I noticed that the system disk (2 partitions) gives an error: "redundancy failed", which I take to mean the disks are out of sync.
    My question is: how to proceed without causing damage to the system? (I'm a bit wary of these procedures as I once managed to mirror a damaged system onto a good one:-)
    Advice on the web seems to always suppose that one of the disks is indicated as 'faulty' or 'critical', but that's not the case; both disks are 'Online'

    Further info: I looked at disk-management because I'd noticed various anomalies: the data shares are unavailable over the network and Explorer hangs; big problem, especially together.
    BTW, my data are on a seperate (mirrorred) set, which is fine.
    Server-software, like my media server, webserver, seems to function OK too.

    Should I break the mirror? Try to 'reactivate' the volume? Thanks for your advice!
    Monday, November 25, 2019 4:15 PM

All replies

  • See:

    Troubleshooting Disk Management

    S.Sengupta,Microsoft MVP Windows and Devices for IT, Windows Insider MVP

    Tuesday, November 26, 2019 12:25 AM
  • Thanks for the link, but none of the cases discussed matches my problem; there is no indication which disk has a problem; just this message 'failed redundancy'.

    Tuesday, November 26, 2019 12:29 PM
  • I agree with your idea, luckily your data is fine, so:

    From an elevated command prompt run diskpart. Once you're in diskpart, run detail disk and detail volume after selecting the appropriate disk/volume using the select command. This should list the health state of each disk.

    Then try to reactivate Disk.

    There is a good link worth reading.

    Please Note: Since the website is not hosted by Microsoft, the link may change without notice. Microsoft does not guarantee the accuracy of this information.


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    Wednesday, November 27, 2019 6:26 AM
  • Thanks for your advice, Teemo. I used diskpart: it reports both disks as 'healthy'.
    The link you provided wasn't much help as it, as other articles, departed from the supposition that, somehow, I could tell which disk was responsible for the 'failed redundancy' error. But that's the problem: I can't.
    Meanwhile, for lack of a better strategy, I broke the mirror; then reinstalled it. No problems: after some hours of resynchronising my system once more looks completely OK.
    But of course I know at least one disk is problematic. I wish Windows would let me know WHICH DISK caused the error.
    Anyway, I will replace both disks with new ones. I've got a 50% chance of replacing the 'problematic' disk first; I hope I choose the right one.
    Thursday, November 28, 2019 3:22 PM
  • A good idea, if you need further assistance, feel free to let me know. 

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    Tuesday, December 3, 2019 9:00 AM