Hi Yasmin, Fitri,
Welcome to the Microsoft Q&A Platform! Thank you for asking your question here.
The upgrade process currently requires deleting the Basic Load Balancer once the upgrade to Standard is initiated. This design choice may be due to Azure's resource management policies, which prevent mixing Basic and Standard SKU resources.
You can back the old LB in the json file at the specified path.
Start-AzBasicLoadBalancerUpgrade -ResourceGroupName <loadBalancerRGName> -BasicLoadBalancerName <basicLBName> -StandardLoadBalancerName <newStandardLBName> -RecoveryBackupPath C:\BasicLBRecovery
In Azure Feedback Hub forum requesting this feature. All the feedback shared in these forums are monitored and reviewed by the Microsoft engineering teams responsible for building Azure
Thanks,
Rohith
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