It's also worth noting that you should check whether any software installed on the server is looking for files currently on the Data drive, because when you merge those partitions any references to d: will be invalid. So plan for this and make sure you have ILO/IDRAC access. To be clear, you are going to have to reboot the server to complete this operation regardless of what tool you use, because you're looking to modify the partition where the OS is installed. That might be a different physical disk on the same system, a removable drive, or whatever other storage options you have available.
somewhere other than the disk where you are modifying partitions. For clarity, when I say 'backup the 80GB of client data' I mean to a completely separate storage location i.e.
