##create $SAS
$sas = Grant-AzureRmDiskAccess -ResourceGroupName shui -DiskName shuitest -DurationInSecond 3600 -Access Read
$destContext = New-AzureStorageContext –StorageAccountName contosostorageav1 -StorageAccountKey 'YourStorageAccountKey'
Start-AzureStorageBlobCopy -AbsoluteUri $sas.AccessSAS -DestContainer 'vhds' -DestContext $destContext -DestBlob 'MyDestinationBlobName.vhd'