Azure ARM JSON template deployment logic clarificatrion

Question

i have a simple question about ARM templates deployment logic.

I have 2 storage accounts (A and B) in my template and I can successfully deploy them to a single resource group.

Now, I remove the storage account B from the template and I deploy the template againt on the same resource group.

What actually happens? nothing? Or should I expect ARM to delete the storage account B keeping only A?

Thanks, F

Answer 1

There are 2 deployment modes in the ARM paradigm: complete and incremental.

Complete will delete all the resources from your resource groups that are absent from the template, so if you only have 1 storage account in your template all the resources except this storage account will get removed.

Incremental will just créate\\update the resources you are declaring in the ARM template. It wont delete anything.

Answer 2

You should expect the ARM template deployment to remove Storage Account B (as long as it doesn't have something dependent on it that would prevent it from being deleted) if you are doing a complete deployment. If an incremental deployment is being used Storage Account B will not be removed.