Better than previous version, Windows Server 2008 has new "Shrink Volume" and "Extend Volume" functions in native Disk Management tool. When C: drive is getting full in Windows 2008 server, many people try to extend C drive with this native tool but failed. Because Extend Volume option is disabled for C drive after shrinking D or other partition. This article introduces the reasons why Extend Volume greyed out in Windows Server 2008 (R2) Disk Management and how to solve this problem easily.
Why extend C drive greyed out in Windows Server 2008 R2
Reason 1. No adjacent Unallocated space on the right
First of all, you should know that the size of a physical hard disk is fixed, a 250GB disk can't be decreased to 200GB or increased to 500GB. Before extending a partition, there must be Unallocated space on the same disk.
Therefore, if you did not delete or shrink another volume to get Unallocated space, of course you cannot extend partition. In that case, Extend Volume option is disabled in Windows Server 2008 for all partitions.
If you delete a partition, all files in it will be deleted, too. But if you shrink this partition, all files will keep intact and only part of free space will be converted to Unallocated. If this partition is used for programs or some Windows services, it can't be deleted.
So many people try to make Unallocated space by shrinking partition. But as you see in the screenshot, Extend Volume greyed out for C and E: drive after shrinking partition D. This is because:
In short, Unallocated space that shrunk from D is nonadjacent to C drive, so Extend Volume is disabled. This is the most common reason why extend C drive greyed out in Windows Server 2008 (r2) Disk Management.
Reason 2. Different partition type
Some people are wondering if it is possible to enable Extend Volume for C drive by deleting the right contiguous partition D. The answer is yes on a GPT disk, but to MBR disk, it depends.
System C: drive is always Primary, if the right contiguous partition D (or E) is Logical, Extend Volume still greyed out for C drive after deleting D.
In Windows Disk Management, Unallocated space that deleted from a Primary partition can't be extended to any Logical drive. Free space that deleted from Logical drive can't be extended to any Primary partition.
Free space that deleted from a Logical drive is still part of the "Extended partition". To convert it to Unallocated, you must delete all other Logical drives and the entire Extended partition. Obviously, it is a bad idea.
2. Other reasons why extend volume greyed out in Server 2008 R2
To data volume, there are 2 additional reasons why Extend Volume greyed out in Windows Server 2008 (r2) Disk Management.
Reason 3. Unsupported file system
From Microsoft explanation, Extend Volume can only expand the partitions that are formatted with NTFS or without file system (RAW).
Another common FAT32 as well as any other types of partitions are not supported.
To show you this limitation, I converted D drive from NTFS to FAT32, as you see in the screenshot, both Shrink and Extend Volume are grayed out, although there is adjacent Unallocated space on the right.
Reason 4. 2TB limitation on MBR disk
Nowadays, hard disks are much larger and it is common to use 2TB+ physical disk or over 10TB RAID array on a server. The problem is, if you initialized the disk as MBR, you can use only 2TB space, the remaining space can't be used to create new volume or added to other volume in Disk Management.
As the screenshot shows, drive H is formatted as NTFS and there is contiguous Unallocated space on the right side, but Extend Volume still greyed out.
In this case, when you right click the Unallocated space in Disk Management, all options are grayed out.
Methods when Extend Volume is disabled in Windows Server 2008
It seems a bit complicated, but it is very easy to solve these problem with NIUBI Partition Editor. Firstly, check your server disk partition layout and find out the reason why Extend Volume greyed out in your server, then follow the corresponding method below.
Solution 1. Move Unallocated space next to C drive
If you have shrunk drive D (or E) to get Unallocated space with Disk Management, NIUBI Partition Editor can move partition D to the right, then Unallocated space will be to contiguous to C drive.
Download this program and you'll see the main window with disk partition layout and other information. There is 20GB Unallocated space in Disk 0 which is shrunk from drive D.
Steps when Extend Volume greyed out in Server 2008 R2 for C drive:
Step 1: Right click D: drive and select "Resize/Move Volume", put the mouse pointer in the middle of D drive and drag towards right in the pop-up window.
Step 2: Right click C: drive and select "Resize/Move Volume" again, drag right border towards right in the pop-up window.
Step 3: Click Apply on top left to execute. (All operations before this step only work in virtual mode)
Solution 2. Resize partition with NIUBI Partition Editor
If you want to extend a FAT32 partition, or extend a Primary partition by shrinking a Logical drive (and vice versa), follow the steps in the video to resize partition with NIUBI:
Solution 3. Convert MBR disk to GPT before extending
If you want to extend a partition to past 2TB or use 2TB+ space, you need to convert MBR to GPT in advance, follow the steps in the video:
Besides shrinking, moving and extending partition to fix Extend Volume greyed out issue in Windows Server 2008/2012/2016/2019/2022, NIUBI Partition Editor helps do many other disk partition management operations such as merge, copy, wipe, hide, defrag, scan partition.