If you delete a VM in the Azure Portal only the compute object is deleted.
This means the os disk with file system and all folders and files is still available (and you are charged for it).
It's easy to verify:
- Create a VM
- Delete the VM
- Click on "All resources" in the Azure Portal and search for the computer name.
- There should be a disk object with the name
You have to delete the orphaned disk manually in the Azure Portal.
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