Not able to upgrade VMSS with Flexible -- Orchestration mode but Loadbalancer needs upgrade

Question

Hi Team,
We have created VMSS with flexible Orchestration mode which is not supporting upgrade policy.
But we need to create this VMSS with load balancer, and load balancer when backend pool added its gives the error like
"""' Backend pool 'vmssbackendpool' was added to Virtual machine scale set 'vmssname'. Upgrade all the instances of 'vmssname' for this change to work """
Now we are not able to upgrade the VMSS.
Please support in this request.

Answer 1

Hi,

The error message you mentioned indicates that you need to upgrade all instances of your Virtual Machine Scale Set (VMSS) in order to apply the changes related to the addition of the backend pool to the load balancer.

In a VMSS, each instance is a replica of the same virtual machine, and changes to the configuration or setup of the instances usually require upgrading them. The upgrade process ensures that all instances have the same configuration and are in sync with the desired state.

Since you mentioned that you have created the VMSS with the flexible orchestration mode, which doesn't support the upgrade policy, you'll need to manually upgrade the instances to apply the changes.

Here are the steps to upgrade the instances in your VMSS:

Identify the name of your VMSS: In the error message, 'vmssname' refers to the name of your VMSS. Replace it with the actual name of your VMSS in the following steps.

Upgrade the instances: You can upgrade all the instances in the VMSS by running the following Azure CLI command:

az vmss update-instances --name vmssname --instance-ids '*' --resource-group yourResourceGroup

Monitor the upgrade progress: az vmss list-instances --name vmssname --resource-group yourResourceGroup --output table

Regards,

Karthik Srinivas

Answer 2

As seen in screenshot with Flexible its not allowed to upgrade from cli as well as from portal. Please let me know how can this issue be resloved.

Answer 3