This article introduces why Extend Volume greyed out in Windows Server 2012 R2 Disk Management, and what to do when Extend Volume option is disabled for C: or D: drive.
To help manage server storage device, Microsoft provides Disk Management component, which is installed by default. In Windows Server 2012 Disk Management, you can create, delete, format volume and change drive letter. Besides the basic management operations, you can change partition size with advanced Shrink Volume and Extend Volume functions.
Extend Volume can extend system partition and data volumes without losing data (in most cases). However, it has many limitations and works under very restricted condition. Thus, many people feedback that Extend Volume greyed out in Windows Server 2012 (R2) Disk Management. In this article, I'll introduce all probable reasons and how to fix this issue.
Why Extend Volume greyed out in Server 2012 Disk Management
There are many reasons why Extend Volume is disabled in Windows Server 2012 (R2) Disk Management, I'll show you one by one.
Reason 1: No Unallocated space
The size of a physical disk is fixed. Before extending a partition, there must be Unallocated space. A 500GB disk can't be decreased to 400GB or increased to 600GB. You can resize a partition, but you can't resize a disk (except virtual disk).
So, if you right click a volume without Unallocated space, of course Server 2012 Extend Volume is grayed out. To get Unallocated space, you may either delete or shrink an existing partition.
Reason 2: Unallocated space is nonadjacent
This is the most common reason why Extend Volume greyed out in Server 2012 r2 Disk Management.
Shrink Volume can only make Unallocated space on the right side while shrinking a partition, but this Unallocated space can only be combined to the left contiguous partition via Extend Volume.
As you see, Extend Volume is disabled for C: and E: after shrinking D: drive. Because C is non-adjacent and E is on the right of this Unallocated space.
Reason 3: File System is not supported
From Microsoft explanation, Extend Volume function only support expanding the partitions that are formatted with NTFS or without file system (RAW).
If this partition is FAT32 or any other types, Extend Volume is grayed out even if there is right adjacent Unallocated space.
Reason 4: Free space can't be extended to Primary partition
In most of servers, system partition C is NTFS and Primary. If the right contiguous volume D is a Logical drive, you still cannot extend C: drive even after deleting D.
After deleting a Logical drive, its disk space will be changed to Free. Unlike Unallocated space, Free space is still part of the Extended partition. To convert it to Unallocated, you must delete all other Logical drive and the entire Extended partition.
As you see, disk space of D is shows as Free and Extend Volume option is disabled for C: drive after deleting D.
Reason 5: Unallocated space can't be extended to Logical partition
Similarly, Unallocated space deleted from a Primary partition cannot be extended to any Logical drive via Server 2012 Disk Management.
Reason 6: 2TB limitation on MBR disk
If you initialized a 2TB+ disk as MBR, you can use only 2TB space, the remaining space can't be created new or added to other volume in Disk Management.
As the screen shot shows, F: drive is formatted with NTFS and there is right contiguous Unallocated space, but Extend Volume still greyed out.
In this case, when you right click this Unallocated space in Disk Management, all options are grayed out.
How to fix Windows 2012 Server Extend Volume grayed out issue
If you have got Unallocated space by shrinking the adjacent D drive, you need to move Unallocated space to the left side, then Extend Volume will be enabled for C drive.
Download NIUBI Partition Editor and you'll see the main window with disk partition structure and other information. There is 20GB Unallocated space that is shrunk from D drive via Disk Management.
Steps to fix Windows Server 2012 Extend Volume greyed out by moving partition:
Step 1: Right click D: and select "Resize/Move Volume", drag middle position towards right in the pop-up window:
Step 2: Right click C: and select "Resize/Move Volume" again, drag right border towards right in the pop-up window.
Step 3: Click Apply on top left to take effect to real disk partition. (The operations before clicking Apply just work in virtual mode.)
When there is contiguous Unallocated space on either side of the partition that you want to extend, you can combine it with NIUBI Partition Editor by 1 step, no matter this partition is NTFS or FAT32, Logical or Primary partition. If Unallocated space is nonadjacent, you can move and then combine it.
Watch the video how to fix Extend Volume greyed out in Windows Server 2012 r2:
If Extend Volume greyed out for a 2TB partition on MBR disk, follow the steps in the video to convert MBR to GPT and then extend partition.
When Extend Volume is grayed out in Server 2012 (R2) Disk Management, find out the associated reason on your server and follow the corresponding method above. Besides shrinking, moving and extending partition, NIUBI Partition Editor helps you merge, copy, convert, hide, wipe, defrag, scan partition and much more.