Unallocated

You need to use the "start" parameter to restore an image to unallocated space through command-line

Explanation of why there can be up to 7.8 MBytes of unallocated space that cannot be removed by usual means

You need to have unallocated space on the disk with the partition the size of which you intend to increase

The issue is only with Acronis Bootable Media. As a workaround, convert the disk from Windows