How to increase partition size in Windows Server 2012?

by John, Updated on: July 5, 2020

This article introduces how to increase partition size on Windows Server 2012 R2. Increase size of system partition or data drive D, E without data loss.

After running the server for a period of time, it is very common that a drive runs out of space, especially to system partition C. In this situation, nobody likes to waste a long time to recreate partitions and restore from backup. It can't be better if you can increase partition size without losing data fast and easily.

Windows Server 2012 Disk Management has built-in Extend Volume function to help increase size of allocated partition. However, it only works by deleting other partition, so it is useless in most cases. Third party software is better choice, but you'd better back up first and run the safest tool. In this article, I'll show you detailed steps to increase partition size for Windows 2012 server. Select corresponding method according to your own disk partition structure.

1. Increase partition size in Server 2012 Disk Management

As I said above, before extending a partition with Disk Management, you must delete another one, there's Shrink Volume function, why not shrinking partition without losing data?

Extend volume disabled

As you see in my server, the 20GB Unallocated space was shrunk from D: drive, Extend Volume is greyed out for both C and E drive. This is because:

  • Extend Volume can only merge Unallocated space to left contiguous partition. In my server, E is on the right and C is nonadjacent to C drive, so Extend Volume is disabled.
  • If Shrink Volume can make Unallocated space on the left side, C drive can be extended easily, but Disk Management doesn't give you this option.

Therefore, if you want to increase C: drive space with Disk Management, you have to delete D to get contiguous Unallocated space. If there's no contiguous volume on the right or you cannot delete it, native Disk Management cannot increase partition size for Windows 2012 server.

If D is Logical drive, Extend Volume is still disabled for C: drive after deleting D, learn why.

2. How to increase system partition size in Windows 2012 server

Comparing with Server 2012 Disk Management, third party partitioning software has many advantages such as:

There are many software to help decrease and increase partition size in Windows Server 2012/2016/2019, but as I said above, you'd better select the safe one, because there's potential system damage and data loss risk. Better than other software, NIUBI Partition Editor has innovative technologies such as:

Download NIUBI Partition Editor and you'll see all disk partitions with structure and other information. In my server 2012, there is C, D, E and system reserved partition in Disk 0. Original C: drive is 40GB and D: is 70GB.

NPE Server

Steps to increase system partition size on Windows Server 2012 r2:

Step 2: Right click D: and select "Resize/Move Volume", drag left border towards right in the pop-up window. (Or enter an amount in the box behind Unallocated space before)

Shrink D

Drive D shrank

Drive D: is shrunk and Unallocated space is made on its left side.

Step 2: Right click system partition C: and select "Resize/Move Volume" again, drag right border towards right to combine Unallocated space.

Extend C drive

C drive extended

C drive is increased from 40GB to 60GB in virtual mode.

Step 3: Click Apply to take effect to real disk partitions.

Watch the video how to increase size of system partition C in Windows Server 2012:

Video guide

If you use VMware, Hyper-V or any types of hardware RAID arrays, the steps are the same. If you want to increase size of system reserved partition follow the steps.

3. How to increase partition size of D (data drive)

When expanding a data volume for Windows 2012 server, there are 2 common options.

When there is plenty of free space on the same disk, follow the steps in the video to shrink C drive or other data volume:

Video guide

When there is not plenty of free space on the same disk, follow the steps in the video to move partition D to another disk:

Video guide

4. How to increase volume size with another disk

In some servers, system partition C is full but there is no other partition on the same disk, or the entire disk is small and you can't get free space from other partitions. Then you need to copy this disk to another larger one. No partitioning software can add space to C drive from another separate disk.

Note: Unlike data volume, C: drive is where Operating System running from, copying single C: drive cannot ensure Windows bootable.

How to increase partition size in Windows Server 2012 with another larger disk:

Video guide

In Summary

Windows Disk Management is useless if you want to increase size of a partition by shrinking another one. NIUBI Partition Editor provides full solution to help accomplish this task fast and safely, no matter you want to increase system partition size or add disk space to any data volumes. Besides changing partition size, it helps you do many other operations.