When attempting to add a second SQL VM to a SQL VM Group getting a ping failure

Question

When attempting to add a second SQL VM to a SQL VM Group getting a ping failure

Rob Lee 0

I can create the SQL VM Group successfully, add the first SQL VM to it and everything works as expected there. The cluster is created and the node is added to it. However, when I attempt to add a second SQL VM I get this error:

Error code: NodeUnreachable, Message: An exception occurred during a Ping request. An exception occurred during a Ping request. No such host is known.

I can ping both the cluster and first SQL VM from the second SQL VM.

I created the SQL VM Group with New-AzSqlVmGroup and am using Update-AzSqlVm to add the VMs to the group. Failover Clustering does get installed on all VMs.

I also manually added the second SQL VM to the cluster through Failover Cluster manager and that worked fine. It appears something is going on with Update-AzSqlVm that is failing to work properly.

Both VMs are in East US. One is in AZ 1 and the other is in AZ 3. Each is in a different subnet and the SQL VM Group is set to MultiSubnet for the cluster subnet type.

Why am I getting this ping failure?

Sai Raghunadh M 4,575 Reputation points Microsoft External Staff Moderator

2025-02-18T00:38:02.7+00:00

Hi @Rob Lee

Thanks for the Question and using Microsoft Q&A

As per my understanding, when you are adding second SQL VM you are getting the error.

Possibilities for getting this error:

Ensure the account used to add the node has administrative privileges on all nodes of the cluster.

Verify that the DNS settings are correctly configured on both VMs. Misconfigured DNS can lead to "No such host is known" errors.

Please do check all the prerequisites and permissions

Please go through this similar thread and documentations that might help you:

https://learn.microsoft.com/en-ie/answers/questions/1725202/trying-to-add-a-node-to-a-sql-cluster-and-i-am-get

https://learn.microsoft.com/en-us/azure/azure-sql/virtual-machines/windows/availability-group-az-commandline-configure-multi-subnet?view=azuresql&tabs=azure-powershell

I hope this information helps, please do let us know if you have any Queries.
Rob Lee 0 Reputation points

2025-02-18T14:45:26.77+00:00

Unfortunately, none of that is helpful
PratikLad 1,905 Reputation points Microsoft External Staff Moderator

2025-02-19T09:49:09.9533333+00:00
Hi @Rob Lee

I also manually added the second SQL VM to the cluster through Failover Cluster manager and that worked fine. It appears something is going on with Update-AzSqlVm that is failing to work properly.

As you said when you are adding the SQL VM to the cluster manually it is working fine but when you are doing same thing with Update-AzSqlVm you are error.

There might be an issue with the Update-AzSqlVm command itself. Ensure that you are using the latest version AZ module. You can update it using the following command

Update-Module -Name Az

After this try again to add the SQL VM to the cluster using Update-AzSqlVm

Check the firewall settings on both VMs to ensure that they allow communicate. Firewalls might block ping requests.

I hope this information helps, please do let us know if you have any Queries.
Rob Lee 0 Reputation points

2025-02-19T13:29:52.8466667+00:00

Hi, I am running the command via an ADO release pipeline and a public agent. It's definitely using the latest version. I've also tried running the command from the cloud shell and it gets the same result.

I did turn off all the firewall zones in both VMs to see if that was the issue and it didn't make a difference sadly.

Seems like an issue with Update-AzSqlVm for sure.

4 answers

Your answer

Sai Raghunadh M 4,575 Reputation points Microsoft External Staff Moderator

2025-02-18T00:38:02.7+00:00

Hi @Rob Lee

Thanks for the Question and using Microsoft Q&A

As per my understanding, when you are adding second SQL VM you are getting the error.

Possibilities for getting this error:

Ensure the account used to add the node has administrative privileges on all nodes of the cluster.

Verify that the DNS settings are correctly configured on both VMs. Misconfigured DNS can lead to "No such host is known" errors.

Please do check all the prerequisites and permissions

Please go through this similar thread and documentations that might help you:

https://learn.microsoft.com/en-ie/answers/questions/1725202/trying-to-add-a-node-to-a-sql-cluster-and-i-am-get

https://learn.microsoft.com/en-us/azure/azure-sql/virtual-machines/windows/availability-group-az-commandline-configure-multi-subnet?view=azuresql&tabs=azure-powershell

I hope this information helps, please do let us know if you have any Queries.
Rob Lee 0 Reputation points

2025-02-18T14:45:26.77+00:00

Unfortunately, none of that is helpful
PratikLad 1,905 Reputation points Microsoft External Staff Moderator

2025-02-19T09:49:09.9533333+00:00

Hi @Rob Lee

I also manually added the second SQL VM to the cluster through Failover Cluster manager and that worked fine. It appears something is going on with Update-AzSqlVm that is failing to work properly.

As you said when you are adding the SQL VM to the cluster manually it is working fine but when you are doing same thing with Update-AzSqlVm you are error.

There might be an issue with the Update-AzSqlVm command itself. Ensure that you are using the latest version AZ module. You can update it using the following command

Update-Module -Name Az

After this try again to add the SQL VM to the cluster using Update-AzSqlVm

Check the firewall settings on both VMs to ensure that they allow communicate. Firewalls might block ping requests.

I hope this information helps, please do let us know if you have any Queries.
Rob Lee 0 Reputation points

2025-02-19T13:29:52.8466667+00:00

Hi, I am running the command via an ADO release pipeline and a public agent. It's definitely using the latest version. I've also tried running the command from the cloud shell and it gets the same result.

I did turn off all the firewall zones in both VMs to see if that was the issue and it didn't make a difference sadly.

Seems like an issue with Update-AzSqlVm for sure.

Answer 1

Rob Lee 0

Figured out the issue. Update-AzSqlVm takes a name as a parameter. This name is the VM name and has no relevance outside of being the resource name. I'm sure it's pertinent to the IaaS agent but internal to Windows it is meaningless. When adding the second node to the cluster, it is trying to use the VM name instead of computer name and thus failing to find it. I suppose MS expects people to either name the VM and Computer the same or add the VM name to DNS. Neither of these options is favorable and it really seems like this is a huge bug in Update-AzSqlVm.

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Answer 2

LiHongMSFT-4306 31,621

Duplicate post

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Answer 3

LiHongMSFT-4306 31,621

Duplicate post

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Answer 4

LiHongMSFT-4306 31,621

Hi @Rob Lee

I can ping both the cluster and first SQL VM from the second SQL VM.

That is quite weird, have you double checked the hostname?

Besides, if you're using a multi-subnet cluster, please configure as a multi-subnet cluster and set the IP address resource dependency to OR.

See: SQL Server Multi-Subnet Clustering (SQL Server)

Best regards,

Cosmog

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When attempting to add a second SQL VM to a SQL VM Group getting a ping failure

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