By AOMEI / Last Updated December 4, 2019

The Symptom

When one of your partition, especially system partition, in Windows Server 2016, is in low disk space, you may want to extend the partition with built-in tool Disk Management that has the ability to extend a partition.

Unfortunately, you are most likely to find out that the option Extend Volume greyed out in Windows Server 2016/2019. What caused this problem? This article will give you the clear reasons and solutions behind this situation.

What caused Disk Management Extend Volume grayed out?

Disk Management does have some restrictions regarding the ability to extend partition, which will result in Extend Volume grayed out.

1. The extend volume or shrink volume feature only works with NTFS file system. If the partition you want to extend is not formatted with NTFS, the Extend Volume option will be grayed out.

Extend Partition 1

2. It is unable to extend volume in Windows Server 2016 when there is no contiguous unallocated space or free space on the hard drive.

Extend Partition 2

3. There is contiguous unallocated space, but it is on the left of the partition to be extended.

Extend Partition 3

4. If you want to extend a primary partition, the Extend Volume will not be available when there is a free space (in the extended partition) instead of unallocated space after the partition needs extending. Similarly, it will not work trying to extend a logical partition when unallocated space is in the way.

Extend Primary Partition

Since Disk Management doesn’t have the ability to move partitions or volumes, you need to delete one or more existing partitions to make the Extend Volume available in Disk Management. Just make sure you backup the important data before you try. Fortunately, you can use a disk partitioning tool AOMEI Partition Assistant that can extend a partition, primary or logical, without data loss.

How to Extend Volume When Greyed Out?

Partition manager for Windows Server 2019/2016/2012/2008, AOMEI Partition Assistant Server allows you to extend partitions formatted with FAT 32 or NTFS. With the Move Partitions feature, you are able to extend partition even when there is no contiguous unallocated space on the hard disk. It doesn’t distinguish free space and unallocated, so you can extend a partition with free space or unallocated space.

Besides, it provides the ability to convert primary partition to logical without losing data, and vice versa. What’s more, with the ability to merge partitions, you can easily extend partition in any cases without losing data. let’s see how it works:

1. Download, install and launch AOMEI Partition Assistant Server.

2. In the main interface, right click the partition and select the option "Merge Partitions".

Merge Partitions

3. In the pop-out window, check the adjacent partition or unallocated space to be merged.

Choose Unallocated Space

4. Preview the partition layout. If it doesn’t meet your needs, you can just click Undo to go back to any step you want. When everything is perfectly checked, Click Apply to apply all the changes.


In conclusion, with AOMEI Partition Assistant, you can easily extend a partition under any of the situations that caused Extend Volume grayed out in Windows Server 2016/2019. Additionally, it provides many other useful features, such as Convert to GPT/MBR disk without data loss, Copy Disk, and Quick Partition.