Many server administrators need to repartition hard drive and extend system partition after running the server for a period of time, but it is not an easy task if you have no such experience before. Because there's potential system and partition damage risk, you'd better back up first and run safe server partitioning tool. Windows Server 2012 has its native tool, but because of many limitations it is not the best choice.
The same with previous version, Windows Server 2012 provides built-in Extend Volume function in Disk Management tool, which can be used to expand both system partition and data volumes without losing data. In fact, Extend Volume is the GUI version of "Extend" command in DiskPart. Both native tools have serious restrictions that cause you unable to extend volume on Server 2012.
Extend Volume restrictions:
Another Shrink Volume function only support NTFS partition, too. The worst, it can only shrink a volume towards left and generate Unallocated space on the right side. This space cannot be extended to any other volume. In other words, if you want to extend a volume by shrinking other one in Server 2012 Disk Management, it is impossible.
As you see, after shrinking drive D the 20GB Unallocated space is nonadjacent to C and on the left side of E, so Extend Volume is grayed out for both partitions.
From the screenshot above, the 20GB Unallocated space can only be extended to left contiguous drive D. If you want to extend C drive with Disk Management, the only option is by deleting drive D to get right adjacent Unallocated space. (Disk Management cannot expand the last partition E)
Steps to extend volume with Windows Server 2012 Disk Management:
If you cannot or do not want to delete partition, server partition software is needed to extend volume on Windows Sever 2012.
Comparing with Windows Disk Management, NIUBI Partition Editor has many advantages such as:
There are many server partitioning software and they are much more powerful than Disk Management, but not all are safe enough to shrink and extend disk partition. If any software caused a disaster, it costs a long time to restore everything.
NIUBI has 3 technologies to protect system and data:
It is also 30% to 300% faster because of its advanced file-moving algorithm.
Download NIUBI Partition Editor, you'll see all disks with partition structure on the right, available operations to selected disk or partition are listed on the left side and by right clicking.
Detailed steps to extend volume on Windows Server 2012 R2:
Step 1: right click drive D: and select "Resize/Move Volume" to shrink it.
If you drag left border towards right, or enter an amount in the box of Unallocated space before:
Then Unallocated space is generated on the left side of D.
Step 2: right click drive C: or E: and run "Resize/Move Volume" again to expand it.
To extend system drive C, drag right border towards right in the pop-up window.
Then Unallocated space is extended into C: drive.
Step 3: Click Apply on top left to confirm and execute.
If you want to extend volume C by shrinking the non adjacent E, there's an additional step to move partition D.
Watch the video how to extend partition in Windows Server 2012 R2 by shrinking other volume:
It is very common to use hardware RAID arrays for a server, some server use RAID 1 for Operating System, RAID 5 for data storage, some server us RAID 5 for both OS and data.
When shrinking and extending RAID partition in Windows Server 2012, do not break array no matter you use RAID 0, 1, 5, 10 or any other types. Do not do any operations to any brand of RAID controller, just follow the steps above.
If there's no available free space in a physical or RAID virtual disk, no software can extend a partition by adding free space from another separated disk. In that case, follow the step to clone disk to a larger one and extend partition(s) with additional disk space.
If you run Windows Server 2012 as guest virtual machine in VMware or Hyper-V, there's also no difference to extend volume if you can shrink any other one on the same virtual disk.
If there's no available free space, you can increase disk size without copying to other one, follow the guide below:
After expanding disk, additional disk space will be shown as Unallocated on the end of original disk. Follow the method in the video and combine Unallocated space to other partition(s).
Because of the inherent limitations, the built-in Disk Management (and Diskpart command) can only help you extend NTFS partition by deleting the right contiguous one. To extend volume on Windows Server 2012 (R2), 3rd party software is better choice. However, you'd better back up first and use reliable tool. As the safest disk partition software, NIUBI Partition Editor helps you shrink, extend and move partitions easily and safely. It also helps you do many other operations.