migrating Azure VM from one tenant to another

Azure documentation talks about migrating a VM from one region to another region - https://learn.microsoft.com/en-us/azure/resource-mover/tutorial-move-region-virtual-machines

https://argano.com/insights/articles/microsoft-azure-clone-vm-how-to-clone-a-vm-in-azure.html

(this seems to be within same tenant)

But we wanted to shift from one tenant to another. Following this post, 
https://medium.com/@morsi.masmoudi/complete-guide-to-cloning-and-moving-a-vm-from-one-azure-tenant-to-another-8fa65dd6955a

but with some changes - instead of a file share, creating a disk from snapshot seems to need a blob container for the "Create Managed Disk" applet nowadays. Following the exact steps as above results in not finding any container in that storage account.

Shifted using the following steps:

1. Enabled CLI maintenance mode on the Moodle instances with 
sudo -u www-data /usr/bin/php admin/cli/maintenance.php --enable
- verified that this does stop the cron also, which would otherwise hit the database every minute.

2. Shut down the database VM, went to its OS disk, created snapshot, went to the snapshot's page, "Export snapshot", copied the export snapshot url. 

3. I had earlier created a test VM in the destination tenant, in the Central India region which is the cheapest at present. Had also created a storage account, and a blob container. Also, had installed azcopy on that VM with the following - https://www.thomasmaurer.ch/2019/05/how-to-install-azcopy-for-azure-storage/

#Download AzCopy

wget https://aka.ms/downloadazcopy-v10-linux

 

#Expand Archive

tar -xvf downloadazcopy-v10-linux

 

#(Optional) Remove existing AzCopy version

sudo rm /usr/bin/azcopy

 

#Move AzCopy to the destination you want to store it

sudo cp ./azcopy_linux_amd64_*/azcopy /usr/bin/

4. Created SAS token (Shared Access Signature) from Azure portal > thestorageaccount - the default 3600 seconds may be too short if we need to do multiple operations. Enabled container, blob and file, all three, and copied the blob url and sas token strings. The blob url would be of the form https://storageaccountname.blob.core.windows.net/?sv=SAS-token - we need to edit this, and add nameofourcontainer/desired-name-of-file.vhd before the ?sv=SAS-token

5. SSH'd into that VM, and ran azcopy. (I could have avoided creating the VM, installing azcopy etc by using an Azure shell instead.) The command will be of the form:

azcopy copy "https://md-abcefg12nmg.z12.blob.storage.azure.net/snapshot/abcd?sv=2018-03-28&sr=b&si=this-is-the-snapshot-url-1234566b61d3&sig=zj9jh0ABCDEDFGHHJtnkD9yK0rvJ44I%3D" "https://lmsmigratestorage.blob.core.windows.net/testcontainer/LMSDBsnapshot.vhd?sv=2024-11-04&ss=bfqt&srt=sco&sp=abcdefghytfx&se=2025-04-21T11:49:12Z&st=2025-04-20T03:49:12Z&spr=https&sig=qwertyuiopasdfghjkABCDEFGuLYlgBQlWZE%3D"

# Actually ran steps 2 and 5 three times, azcopy took the following times:

# Elapsed Time (Minutes): 2.034 <-- LMS db OS disk

# Elapsed Time (Minutes): 1.2004 <-- LMS php disk

# Elapsed Time (Minutes): 22.0734 <-- LMS data disk
 

6. From Azure portal, in the destination tenant, Home > Create > Managed Disks > (Choosing Source as Blob storage) > Browse > choosing our VHD snapshot file in blob storage. Creating disk from snapshot, creating snapshot etc are very fast operations, these operations complete in less than a minute.  

7. From the created disk, if it is an OS disk, Create VM. Note that in our case, the default "Operating System type" was v1, but our original VM was v2, so I created the new VM also as v2. 

8. The data disk can be attached later to the VM, even when it is running - "Attach existing disk". Caution - attaching an OS disk as data disk does not seem to work properly - that new OS disk becomes the primary OS disk! 

9. In our case, we were cloning the db VM and copying the php files (and postgresql db) from the php server into the db VM, since we wanted to consolidate the two VMs into a single one. So, I had to copy over from the old VM to the new VM using rclone copy. What I needed to copy, and the steps taken, will be a separate post.

(What does not work:

1. "Export disk" and trying to use that using azure cli - this will not work. We need to create a snapshot first, then export the snapshot, and use the snapshot to re-create the disk in the new tenant.

2. Mounting azure blob storage on a VM and using wget to copy the snapshot VHD to blob storage will not help us to create the disk in the new tenant - azcopy is mandatory.

3. wget -O mydisksnapshot.vhd "https://snapshot-export-URL" followed by
azcopy copy mydisksnapshot.vhd "https://blob-storage-url" will work, but takes double the time - azcopy works fine directly from snapshot url to blob storage url. Caveat is that we must make a container first, and then use azcopy copy.)