Inherited VM data disk setup query

The 4 x 4,095 GB Standard HDDs have been configured within the virtual machine using Windows Disk Management, most likely as a spanned or striped dynamic volume. This configuration consolidates the individual disks into a single logical drive, which explains why the system presents a 10.2 TB volume rather than the full 16 TB of raw capacity. Azure exposes each disk independently, but Windows can aggregate them into one volume. Because all disks are allocated to this configuration, no unallocated space is visible. If a smaller capacity is required, the recommended approach is to provision new disks of the desired size, create a new volume, and migrate the data accordingly.

https://learn.microsoft.com/en-us/azure/virtual-machines/windows/attach-managed-disk-portal

https://learn.microsoft.com/en-us/azure/virtual-machines/disks-types

https://learn.microsoft.com/en-us/windows-server/storage/storage-spaces/manage-volumes?tabs=windows-admin-center