Resize system partition

Windows Server 2012 resize/shrink system volume

This article introduces how to resize system partition on Windows Server 2012 R2. Shrink system partition to create new or expand D(E) drive without data loss.

Resize system partition with Disk Management

It can’t be better if you can re-size disk partition if any one is running out of space or due to some other reasons. Besides modifying the parameters of partition and files, when resizing system partition on Server 2012, the boot related files must be updated, too, so comparing with data volumes, it is more complicated to resize system volume.

To shrink and extend system partition on Windows Server 2012, the built-in Disk Management utility can help you, and there is no difference to resize system partition or data volumes. However, because of some limitations you cannot shrink or extend partition with DM.

How to shrink system partition in Server 2012 Disk Management:

  1. Press Windows and X on your keyboard and select Disk Management.
  2. Right click system C drive and select Shrink Volume.
  3. Enter the amount of space and click Shrink to proceed.

Tip: if you cannot shrink system partition with Server 2012 DM in some situations, find out the reasons.

Enter amount
If you want to extend system partition, Server 2012 Disk Management is NOT the best choice, because the built-in Extend Volume is grayed out in most situations.

Extend Volume can only expand the partition with adjacent Unallocated space on the right side. When you shrinking drive D with Shrink Volume, Unallocated space is generated on the right side of D, so it can’t be added into system C drive.

The only way to enable Extend Volume for system C drive is by deleting the contiguous drive D, but if you installed programs or any Windows services are running from D, you cannot delete it.

Luckily, there’s third party software to resize system partition for Windows Server 2012 (R2), however, remember to back up the server and use safe partitioning software. Otherwise, you may lose data or waste a long time to restore and verify.

Shrink system partition to create new volume

To re-size system volume on Server 2012 or other editions, NIUBI Partition Editor is the first choice, which is the safest and fastest tool because of the unique and powerful technologies, for example:

  • 1 Second Rollback – automatically reverts server to original status if any software or hardware issue occur, so server could back online immediately without damage.
  • Virtual Mode – the operations you do will be listed as pending for preview and real disk partitions won’t be modified until you click Apply to confirm.
  • Cancel at will – it helps cancel the ongoing but unwanted operations immediately without losing data.
  • Hot-Resize – change partition size on the fly (close other running programs and files in the volume that you are shrinking or moving).

However, the same with other 3rd-party software, NIUBI requires server reboot to complete shrinking.

Steps to shrink system volume on Windows Server 2012 with NIUBI:

Download NIUBI Partition Editor and you’ll see the main window:

NIUBI main window

Right click the system partition and select “Resize/Move Volume”, drag right border leftwards in the pop-up window.

Shrink C leftwards

System C drive is shrank and Unallocated space is produced on the right side. This Unallocated space can be used to create volume either with NIUBI or Windows DM.

System volume shrank

Tips If you drag left border rightwards in the pop-up window, Unallocated space will be produced on the left side of C drive, which can be used to extend system reserved partition.

Shrink C rightwards

Shrink system volume to extend D or other drive

If you want to shrink system volume C to expand D (the adjacent drive), follow the step above to get Unallocated space on the right side of C drive. Then right click drive D and select “Resize/Move Volume” again, drag the left border leftwards to combine the Unallocated space.

Extend D drive

Partition D will be extended with the Unallocated space.

Drive D extended

If you want to shrink the system partition to expand the nonadjacent drive E, do NOT combine the Unallocated space to D drive, instead, you need to move it to the other side.

Right click drive D and select “Resize/Move Volume”, drag the middle position leftwards in the pop-up window:

Move drive D

Then click drive E and select “Resize/Move Volume” again, drag the left border leftwards to combine the Unallocated space:

Extend drive E

In Summary

With NIUBI Partition Editor, you can safely shrink system partition on Windows Server 2012 (R2) and generate Unallocated space on either side. And then you can create new volume or expand other contiguous or non-adjacent partition with this Unallocated space.

Tips If you use any types of hardware RAID arrays, do not break the array or do any other operations to the controller, simply follow the steps above.

No partitioning software can extend a volume by taking free space from other separated hard disk.


How to resize/shrink system partition on Windows Server 2012?
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