I am assuming you are already familiar with the Azure admin tasks like creating disks, VMs etc.
- Stop the source Virtual Machine
- Create a new storage account (classic) using the destination Azure subscription
- Move VHDs from source storage account to destination storage account
I used Microsoft Azure Storage Explorer and added both source & destination subscriptions to it. Explorer will show all storage accounts from connected subscription. Then you just need to copy the Blob container from the source storage and paste it to the destination storage account.
- Create an Azure disk with the destination OS VHD you just copied. Use OS VHD at this point and you can add additional disks later.
- Create the Virtual Machine using the disk from the last step.
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