Data Sync - Adding On Prem DB is "AdAzure SQL Data Sync – Unable to Add New On-Premises Databases After Unregistering Previous Databasesd Failed"

Question

Data Sync - Adding On Prem DB is "AdAzure SQL Data Sync – Unable to Add New On-Premises Databases After Unregistering Previous Databasesd Failed"

Murugesh Perumal 0

We are facing an issue with our Azure SQL Data Sync configuration.

The previous on-premises databases/members were unregistered and removed, and we also performed cleanup and restarted the Data Sync Agent. However, we are still unable to add the new on-premises databases to the Sync Group.

When attempting to add the databases, we receive the following errors:

1. DB_12 – Add Failed

Failed to perform data sync operation: Cannot create sync member 'DB_12' because the maximum number of on-premise database as sync member can be created under a sync group is 5 for Basic sync group.

2. DB– Add Failed

Failed to perform data sync operation: The database type passed in is not AzureSqlDatabase for sync member 'DB', update credential failed.

We have already:

Unregistered the previous database members.
Registered the new databases.
Performed cleanup of the previous configuration.
Restarted the Azure SQL Data Sync Agent/server.
Verified that the old database members are no longer visible/registered in the Azure Portal.

However, the system still appears to be detecting the previous on-premises database members or their configuration, resulting in the 5 on-premises database limit error for the Basic Sync Group.

Request:

Could you please investigate whether there are any stale, orphaned, or hidden sync members remaining in the backend configuration of the Sync Group and remove them if necessary?

SAI JAGADEESH KUDIPUDI 3,640 Reputation points Microsoft External Staff Moderator

2026-08-01T05:46:45.5733333+00:00

Hi @Murugesh Perumal ,
In the portal, do you still see any old on-premises sync members under that same sync group (even if you think they were unregistered)?

Were any of the old on-premises databases unreachable during unregister/cleanup (for example, server offline, firewall change, renamed server, etc.)?

When you restart the client agent service, does the membership list change anywhere in the portal (or does it always appear stuck at the “5” state)?

Is the new on-premises database being added to the same sync group and the same client agent?

Are both the hub and the sync metadata configured in the same Azure region/subscription as before (to rule out broader configuration drift)?
Kindly provide the requested details through a private message so we can investigate the issue further.

1 answer

Your answer

SAI JAGADEESH KUDIPUDI 3,640 Reputation points Microsoft External Staff Moderator

2026-08-01T05:46:45.5733333+00:00

Hi @Murugesh Perumal ,
In the portal, do you still see any old on-premises sync members under that same sync group (even if you think they were unregistered)?

Were any of the old on-premises databases unreachable during unregister/cleanup (for example, server offline, firewall change, renamed server, etc.)?

When you restart the client agent service, does the membership list change anywhere in the portal (or does it always appear stuck at the “5” state)?

Is the new on-premises database being added to the same sync group and the same client agent?

Are both the hub and the sync metadata configured in the same Azure region/subscription as before (to rule out broader configuration drift)?
Kindly provide the requested details through a private message so we can investigate the issue further.

Answer 1

Hi Sai,

I am not seeing any old on-premises sync members in the Azure Portal.

The old server is offline. I added a new server and installed the Sync Agent using the same configuration/name. Initially, I could see four old sync members in an "Unable to Reach" state. I removed them one by one and then added the databases again.

When I add a new database from the Azure Portal, the first database is added successfully and the sync is working. However, it appears to be counted as the 5th on-premises database, even though I can see only one database listed under the On-premises databases section.

When I try to add another database, I receive the error that the maximum limit of five on-premises databases has been reached.

Could you please check if there are any stale or hidden sync member records still associated with the Sync Group in the backend? We are unable to identify or remove them from the Azure Portal.

Kindly help us resolve this issue at the earliest.

regards

Murugesh P.A