@Roshan Jha Please find answers below:
1) While moving VM from East US to West US, found that OSdisk is unable to move. Why is this so? Why OS disk can't be move between regions?
Is the move complete? OSDisk won’t be surfaced as a separate resource type/line item in Azure Resource Mover. However, OSDisk automatically moves when user moves the VM. Refer Move resources to another region with Azure Resource Mover | Microsoft Learn
2) Also facing error while moving VM to different region, it’s telling that VM size is unavailable at destination.
This could be due to the reason that the VM size/SKU is unavailable in the target region. For this you can change the VM size as part of move. Refer Modify destination settings when moving Azure VMs between regions with Azure Resource Mover | Microsoft Learn
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