How to extend C drive in Windows Server 2016 without data loss?

As the latest Windows Server version, Microsoft added new features and improved the performance of Windows Server 2016. However, about disk management ability, nothing new was added, everything keep the same with previous version – Windows Server 2008. In Disk Management snap-in, you can do some basic operations such as create, delete, format partition and change drive letter. With advanced feature – Extend Volume and Shrink Volume, you can change partition size without starting over. However, due to its limitation, if you want to extend C: drive by shrinking D, it is impossible. I’ll explain the reason in the next paragraph. In most cases, to extend C drive in Windows Server 2016, you need 3rd-party partition software.

Extend C: drive in Server 2016 Disk Management

Right-click Windows icon on bottom left and click Disk Management, where you’ll see all connected disk partition, as well as capacity and free space of each partition.

Open disk management

Note: the steps to expand C drive in Server 2016 Disk Management is for the people who insist on using Windows built-in tool but do not know how to operate. It is not the best solution to shrink and extend volume in DM.

Expand C drive with Unallocated space

Only when the Unallocated space is adjacent and at the right side of C: drive, you can use it to extend C drive.

Step 1: Right-click C: drive and select “Extend Volume“.

Disk Management

Step 2: In the pop-up window, you’ll see Extend Volume Wizard, click Next.

Extend Volume Wizard

Step 3: Select disk and available space, click Next.

Select disk

Step 4: Review the selected disk and free space, click Finish to proceed.

Finish Wizard

In a short time, the Unallocated space will be combined into C drive.

What about no adjacent Unallocated space?

If there is no adjacent Unallocated space at right side, when you right-click C drive, you’ll find that the Extend Volume is grayed out.

In this situation, if you still want to expand C drive in Disk Management, the only choice is: delete volume D and follow the steps above to expand C drive.

Note: In some special situations, you cannot get Unallocated space even if you delete drive D. From the screenshot below, Extend Volume is still disabled after deleting D.

Why? In this server, volume D is Logical partition. Different with Primary partition, to convert the disk space in Logical partition to Unallocated space, you should delete all Logical partitions in the Extended partition, and then delete the entire Extended partition.

Cannot extend C

Do not extend C drive by deleting D, reasons:

  1. There should be other device to store files.
  2. It costs long time to transfer files.
  3. There is risk of losing data.
  4. Applications or services that runs from D drive stop working.
  5. You have to delete other volumes together in special situation.

It is much easier if you use 3rd-party server partition software.

Extend C: drive with partition software

Note: data is most important to a server, so you’d better select a safe and reliable software. Different with other read-only software, to change size of a volume, the partition software will modify the start and end position of this volume, move locations of all file in this volume,modify the parameters of this volume in MBR, DBR and other place. So a bad designed software is likely to cause system boot failure, volume corruption and data loss.

Here I recommend NIUBI Partition Editor, the most popular partition software for Windows Server. It is integrated unique Roll-Back protection technology, which is able to roll back the server to the status before resizing automatically and rapidly. The ONLY software that can ensure 100% data safety, even if power failure or other hardware issue occurred during resizing.

Another benefit is much faster, because the file-moving algorithm used by NIUBI Partition Editor is optimized. I’ve tested many times, it is faster indeed (30% – 300% faster according to the website)

Steps to extend system C drive in Windows Server 2016:

Step 1. Download and install NIUBI Partition Editor, right click volume D and select “Resize/Move Volume“.

Select Resize

Step 2: In the pop-up window, drag left border rightwards to shrink D.

Drag to shrink

Shrink d drive

Drag to shrink

Click OK and back to the main window, 20GB Unallocated space generated next to C: drive.

Unallocated created

Step 3: Right click C drive and select “Resize/Move Volume” again. In the pop-up window, drag the right border rightwards to hold the Unallocated space.

Drag to extend

Extend C drive

Extend C

Step 4: Click OK and back to the main window, C drive extended to 60GB by adding the Unallocated space. Click Apply on top left to execute, done.

C drive extended

If there is not plenty of free space in volume D, you can get from other drives, follow the steps in the video.

Is it easy and fast to resize & extend C drive on Windows Server 2016?

Note: if you use VMware, Hyper-V or hardware RAID array, such as RAID 0, 1, 5, 10, there is nothing special, just shrink and extend volume like physical disk partitions.

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