Power shell command for Creating an Operating System disk or Data Disk from a VHD:

To create a bootable Windows OS disk from VHD:
Add-AzureDisk -DiskName "<DiskName>"
              -MediaLocation "http://<StorageAccountName>.blob.core.azure.com/<ContainerName>/
<FileName>.vhd"
              -Label "<Label>"
              -OS "Windows"
To create a bootable Linux OS from VHD:
Add-AzureDisk -DiskName "<DiskName>"
              -MediaLocation "http://<StorageAccountName>.blob.core.azure.com/<ContainerName>/
<FileName>.vhd"
              -Label "<Label>"
              -OS "Linux"

To create a data disk from VHD:

 Add-AzureDisk -DiskName "<DiskName>"
              -MediaLocation "http://<StorageAccountName>.blob.core.azure.com/<ContainerName>/
<FileName>.vhd"
              -Label "<Label>"