Initial Replication sits at 0%. New server with same name as old replicated server

Question

Initial Replication sits at 0%. New server with same name as old replicated server

Antonella Grimaldi 0

I had a server (one of 8) replicated to Azure for DR.

All servers are Windows, Hyper-V, Server 2016, 2019.

I replaced one server and had to give it the same name as the original. Server 2025 on the new.

Original server, replication was turned off and I waited until it was finished and disappeared.

Then the old server was renamed and the new server was renamed to the same as the original.

Starting replication succeeds but never starts the initial replication. 2 days at 0%.

I'm connecting it to the names. Something from the original server is lingering. But what?

There are a lot of things tied to the server name and changing it would be doable but very time consuming.

Suchitra Suregaunkar 1,880 Reputation points Microsoft External Staff Moderator

2025-10-09T11:58:59.0666667+00:00
Hello Antonella Grimaldi

Thank you for posting your query on Microsoft Q&A platform.

The initial replication for your new server is stuck at 0% because Azure Site Recovery (ASR) still holds metadata from the old VM in the Recovery Services Vault. ASR uses a unique machine ID, not just the name, so reusing the same name causes a conflict.

I would suggest to try below steps to resolve the issue:

Step 1: Confirm Cleanup of Old VM

In the Azure Portal, go to:Recovery Services Vault → Replicated Items Ensure the old VM is not listed. If it is, select it and click Disable Replication.

Check Site Recovery Jobs for the Cleanup job. If it failed, re-run it.

Step 2: Refresh Hyper-V Host Discovery

Navigate to: Recovery Services Vault → Site Recovery Infrastructure → For Hyper-V Sites → Hyper-V Hosts

Select the Hyper-V host that now runs the new VM.

Click Refresh Server and wait for the discovery job to complete.

Try enabling replication for the new VM again.

Step 3: Repair ASR Provider (Non-disruptive)

On the Hyper-V host:

Download the latest Azure Site Recovery Provider from Microsoft.

Run the installer and choose Repair.

After repair, go back to the vault and click Refresh Server again.

Step 4: Host Cleanup (If Still Stuck)

If replication still stalls:

On the Hyper-V host that previously hosted the old VM, run this PowerShell cleanup:

net stop dra Remove-Item -Recurse -Path "HKLM:\SOFTWARE\Microsoft\Azure Site Recovery\Registration" -ErrorAction SilentlyContinue Remove-Item -Recurse -Path "HKLM:\SOFTWARE\Microsoft\Azure Site Recovery\ProxySettings" -ErrorAction SilentlyContinue Remove-ItemProperty -Path "HKLM:\SOFTWARE\Microsoft\Azure Site Recovery" -Name "DraID" -ErrorAction SilentlyContinue

Then Refresh Server in the vault. If the host shows as disconnected, re-register it using the vault credentials file.

Step 5: Re-enable Replication

After cleanup, enable replication for the new VM. Initial sync should now progress beyond 0%.

These steps remove the stale identity from the vault and host, allowing ASR to treat the new VM as a fresh entity.

Please refer below official documents for more details:
https://free.blessedness.top/en-us/azure/site-recovery/site-recovery-manage-registration-and-protection

https://free.blessedness.top/en-us/azure/site-recovery/delete-vault

https://www.thomasmaurer.ch/2021/08/hyper-v-host-already-registered-to-azure-recovery-vault-error/

Kindly let us know if the solution shared in the comment addressed your query. If you have any other questions or need further support, please feel free to contact us.

Thanks,

Suchitra.
Suchitra Suregaunkar 1,880 Reputation points Microsoft External Staff Moderator

2025-10-10T00:32:07.3033333+00:00

Hello Antonella Grimaldi

Could you please let us know if the solution shared in the comment addressed your query. If you have any other questions or need further support, please feel free to contact us.

Thanks,

Suchitra.

1 answer

Your answer

Suchitra Suregaunkar 1,880 Reputation points Microsoft External Staff Moderator

2025-10-10T00:32:07.3033333+00:00

Hello Antonella Grimaldi

Could you please let us know if the solution shared in the comment addressed your query. If you have any other questions or need further support, please feel free to contact us.

Thanks,

Suchitra.

Answer 1

Alex Burlachenko 18,310 Volunteer Moderator

Hi Antonella Grimaldi,

you gave a new server the same name as an old one that was previously replicated, and now asr is confused. the old server's metadata is still lingering in the recovery services vault, blocking the new one.

the problem is that azure site recovery uses a unique identifier for each machine it protects. even though you turned off replication for the old server, its identity is still cached in the system, so when you try to protect a new machine with the same name, it hits a conflict and just stalls at 0%.

you need to completely clean up the old server's registration from the vault.

go to your recovery services vault in the azure portal. navigate to 'site recovery infrastructure'. under 'for hyper-v sites', click on 'hyper-v hosts'. find the hyper-v host that contained the old server and select it. in the details, you should see a list of protected servers. if the old server is still listed there, you need to remove it.

after you remove the old server's registration from the vault, the replication for the new server should kick off and start the initial sync almost immediately.

the stalled replication is because the vault still has a record of the old server. clean it out from the 'hyper-v hosts' section of your recovery services vault, and the new one should start replicating.

regards,

Alex

and "yes" if you would follow me at Q&A - personaly thx.
P.S. If my answer help to you, please Accept my answer

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Antonella Grimaldi 0 Reputation points

2025-10-07T18:57:49.2966667+00:00

Alex,

Thanks for your response. I figured it was something lingering after removing the replication. In your steps I get this far:

Recovery Services Vault Site Recovery Infrastructure For Hyper-V Sites Hyper-V Hosts shows two hosts (one is not being used) (shows 8 protected VM’s. Should be 9 with the new one) When I click on the host, it only opens an information page about the host. I don’t get a list of servers. There are no options. (except Refresh Server, Renew Certificate)

The only place I see the server list is where I disabled the replication and it disappeared when that was finished. (Recovery Services Vault - Host - Replicated Items)
Antonella Grimaldi 0 Reputation points

2025-10-22T02:47:32.5733333+00:00

Unfortunately it did not work. I have had to take days to perform the operations. When the new server is setup to replicate but never goes higher than 0%, avhdx files are still created and grow every day. The server has to be restarted to get them to merge. I'm sure there is a powershell that will do it too. However the issue may be after deleting the reg keys. In the Azure portal the host shows Offline. If I refresh it, it takes about 2 hours to time out and fail. Should the certificate be refreshed? Should I put back the reg keys? I did export them. Also, the Host shows all replications occurring as normal. (just not the new server)
Suchitra Suregaunkar 1,880 Reputation points Microsoft External Staff Moderator

2025-10-22T15:22:33.8066667+00:00

Hello Antonella Grimaldi

we are looking into your issue, for that I would like to have some details from your end for Live repro of this issue.

Could you please share us the details that are asked via Private message.

Thanks,

Suchitra.
Suchitra Suregaunkar 1,880 Reputation points Microsoft External Staff Moderator

2025-10-22T15:44:22.0866667+00:00
Hello Antonella Grimaldi

After registry cleanup, the host went Offline, which indicates:

The ASR agent lost its registration and certificate trust.

Refresh attempts fail because the host is no longer authenticated with the vault.

Yes, refresh the certificate. In the vault, renew the certificate and download the latest vault credentials file.

Re-register the Hyper-V host using that file.

Do NOT restore old registry keys, that would bring back stale metadata and defeat the cleanup.

Instead, complete the re-registration process.

Use Merge-VHD or Optimize-VHD to merge disks without rebooting.

Reference: https://free.blessedness.top/en-us/powershell/module/hyper-v/merge-vhd?view=windowsserver2025-ps and https://free.blessedness.top/en-us/powershell/module/hyper-v/optimize-vhd?view=windowsserver2025-ps.

Thanks,

Suchitra.
Suchitra Suregaunkar 1,880 Reputation points Microsoft External Staff Moderator

2025-10-23T17:08:49.2766667+00:00

Hello Antonella Grimaldi

Could you please let us know if the solution shared in the comment addressed your query. If you have any other questions or need further support, please feel free to contact us.

Thanks,

Suchitra.
Antonella Grimaldi 0 Reputation points

2025-10-23T23:47:15.63+00:00

I'm afraid not. When I try to re-register the server I get the message "The vault credentials currently used for registration isn't supported anymore. Download new vault credentials from the azure site recovery portal and retry."
Suchitra Suregaunkar 1,880 Reputation points Microsoft External Staff Moderator

2025-10-24T01:15:03.84+00:00
Hello Antonella Grimaldi Download a fresh vault credentials file

Azure Portal → Recovery Services vault → Properties → Backup credentials → Download the .vaultcredentials file.

Reference: https://free.blessedness.top/en-us/azure/site-recovery/hyper-v-azure-tutorial

Update/Repair ASR components on the host and Re‑register the Hyper‑V host using the new credentials

Run the ASR Registration Wizard and select the fresh .vaultcredentials file.

Host should flip to Online under Site Recovery infrastructure → Hyper‑V Sites → Hyper‑V Hosts.

Reference: https://free.blessedness.top/en-us/azure/site-recovery/site-recovery-manage-registration-and-protection and https://free.blessedness.top/en-us/troubleshoot/azure/site-recovery/getting-started/vault-registration-fails

Thanks,

Suchitra.
Antonella Grimaldi 0 Reputation points

2025-10-25T21:08:23.2566667+00:00

Suchitra, that is exactly what I am doing. I still get that error. I could not repair the ASR because it was looking for a directory that no longer exists. I uninstalled it and reinstalled it. Same error. I have attached the error I am getting and as you can see, the credential file is dated today. HOST-VN01 Error.PNG

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Initial Replication sits at 0%. New server with same name as old replicated server

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