This article explains the reasons why Extend Volume greyed out in Windows Server 2019, and what to do when Extend Volume is disabled in Server 2019 Disk Management.
In Windows Server 2019 native Disk Management, there are built-in Shrink Volume and Extend Volume functions that can be used to resize partition without losing data (in most cases). Many people try to extend C drive with this tool when it is getting full. However, many people feedback that they cannot do this because Extend Volume is disabled for C drive after shrinking D. In this article, I'll explain why Extend Volume greyed out in Windows Server 2019 Disk Management and how to solve this problem with ease.
Why Extend Volume greyed out in Windows Server 2019
Reason 1: no adjacent Unallocated space
The size of a physical hard disk is fixed, a 500GB disk can't be decreased to 400GB or increased to 600GB. Therefore, before extending a partition, there should be Unallocated space on this disk. If you right click a partition without such kind of space, of course Extend Volume is grayed out.
To Unallocated space, you may either delete or shrinking a volume. You'll lose all files in this volume if you delete it, but all files keep intact if you shrink it instead. With Windows Server 2019 Disk Management, it is easy to shrink a partition, but Unallocated space can't be extended to other volume.
Extend Volume function can only extend Unallocated space to the left contiguous partition. As you see in the screenshot, Extend Volume greyed out for C: and E: drive, because C drive is nonadjacent to the Unallocated space, drive E is on the right.
If Disk Management can make Unallocated space on the left side while shrinking partition, you can extend C drive without issue, but Shrink Volume function cannot do this, it only gives you an option to enter an amount of space.
Reason 2: file system is not supported
Extend Volume function can only extend the partition that is formatted with NTFS file system, this is the reason why Extend Volume greyed out in Server 2019 Disk Management when you right click a FAT32 or other types of partitions, even if there's right contiguous Unallocated space.
Reason 3: different partition type
Disk Management cannot extend C drive by shrinking D, some people are wondering whether it's possible to enable Extend Volume by deleting D. The answer is yes to a GPT disk, but to MBR disk, it depends.
In MBR disk, the partitions that you want to delete and extend must be the same type. If one partition is Primary and the other one is Logical, Extend Volume will be disabled even after deleting the right contiguous partition.
Reason 4: 2TB size limit in MBR disk
Another limitation to MBR disk is that the maximum partition size is 2TB. If you initialize a 4TB hard disk as MBR, you can only use 2TB space, the remaining space will be shown as Unallocated and it can't be created as new volume or extended to other volume.
As you see in the screenshot, drive F is NTFS and there's right contiguous Unallocated, but Extend Volume still greyed out.
What to do when Extend Volume is disabled in Disk Management
Solution 1: move and merge Unallocated space
If Extend Volume greyed out for C drive after shrinking D or other volume, you can move Unallocated space next to C drive with NIUBI Partition Editor. To another data volume E, you can merge Unallocated space to it directly without moving.
Download NIUBI Partition Editor and follow the steps in the video:
Solution 2: resize volume with partition editor
If Extend Volume greyed out because you try to extend a FAT32 partition or the type of partitions that you want to shrink and extend are different, resize with NIUBI Partition Editor. There's no difference while resizing NTFS and FAT32 partition, or resizing Primary and Logical partition. Follow the steps in the video:
Solution 3: convert mbr disk to gpt
If you want to extend a partition beyond the limit of 2TB, firstly follow the steps in the video to convert MBR disk to GPT:
Take care of system and data
When Extend Volume greyed out in Windows Server 2019 Disk Management, check your disk partition configuration and find out the exact reason, then follow the corresponding method above.
There's potential data loss risk while changing partition size and location, so remember to make a backup and run safe partition software. Better than other tools, NIUBI Partition Editor has advanced Virtual Mode, Cancel-at-well and 1-Second Rollback technologies to protect system and data. Thanks to the unique file-moving algorithm, it is much faster while shrinking and moving partitions.