Hyper-V Replica Doesn't Seem to Replicate Expanded VHDX File?


  • I'm running Microsoft Windows Server 2012 R2 Essentials as a VM on Microsoft Hyper-V Server 2012 R2 (Server Core).  I am using Hyper-V replica and extended replication to copy the Essentials VM to two backup Hyper-V servers.  This has been working for months.

    This evening my 2 Tb VHDX used by Essentials VM was nearly out of space.  I took down the VM and expanded the VHDX to 4 Tb. Then I restarted Essentials and used Disk Manager to allocate the new 2 Tb to give me a 4 Tb of space for Essentials to use.  The primary VM seems to be working normally.

    But Hyper-V replication doesn't seem to be functioning correctly.  I'm wondering if I'll need to delete the replication and start over since the size of the VHDX increased compared to the original configuration?

    When I try and get replication to resume (from primary to secondary) I am prompted to resync which I have attempted many times. The primary creates a snapshot and then after a few moments the snapshot is merged back into the primary VM. But the VHDX on the secondary still shows it is 2 Tb in size.  So the resynchronization doesn't seem to have completed correctly?  Plus I have the option to "Resume Replication" from the primary which also implies the prior resyncrhonization failed.

    I haven't found any error messages using Server Manager to explain why the resync seems to fail.

    At one point I found I was able to resync from the secondary to the tertiary server.  I don't know what that actually accomplished, but both still have a 2 Tb VHDX instead of the 4 Tb that should now be available.

    Any ideas on how to get replica and extended replica to work without having to delete and start replication over from the beginning?

    Thanks for any assistance.


    Tuesday, September 02, 2014 1:38 AM


  • There was an error message that I'd overlooked and unfortunately this tells me I'll have to delete and restart replication from the beginning.

    Cannot perform operation for virtual machine 'Windows Essentials 2012 R2' as virtual size of one or more virtual hard disks are different between primary and Replica servers. Delete and re-enable replication. (Virtual machine ID xxxxxxx)


    • Marked as answer by WindOfChange Tuesday, September 02, 2014 4:27 AM
    Tuesday, September 02, 2014 4:27 AM