Extend system reserved partition in Windows Server 2016

Published on: November 16, 2019

This article introduces how to increase system reserved partition in Windows Server 2016, shrink C or D drive to extend system reserved partition without losing data.

System Reserved partition is a small hidden partition that contains Windows boot related files. You won't see it in File Explorer but in Disk Management console. In general, there's nothing to do with it, but in some cases you need to expand system reserved partition for Windows 2016 server. For example, before converting MBR system disk to GPT with mbr2gpt.exe, you'd better increase system reserved partition first, otherwise, C drive can't be extended after converting.

Server 2016 DM cannot extend system reserved partition

The same with previous Windows Server 2012, Server 2016 has built-in Extend Volume function in Disk Management, but it cannot extend system reserved partition. Because Extend Volume only works by deleting the contiguous partition on the right. In most cases, the right contiguous partition is system C: drive, of course it can't be deleted.

After shrinking C drive, you'll find that Extend Volume is disabled for system reserved partition in Server 2016 Disk Management.

Cannot extend

While shrinking partition with Disk Management, it only gives you an option to enter an amount, then Unallocated space will be made on the right. If it is able to make Unallocated space on the left, you can extend system reserved partition in Windows Server 2016 without any software.

If you have shrunk C drive in Server 2016 Disk Management, follow the steps to add Unallocated space to system reserved partition:

  1. Download NIUBI Partition Editor, right click C: drive and select "Resize/Move Volume", drag middle position towards right in the pop-up window.
  2. Right click the system reserved partition and select "Resize/Move Volume" again, drag right border towards right to combine Unallocated space.
  3. Click Apply on top left to execute.
  1. Any operations before clicking Apply only work in virtual mode.
  2. It requires server rebooting. (The pending operations that are marked as check symbol can be done in Windows.)

Video guide

How to extend system reserved partition by shrinking C drive

If you did nothing before, you can shrink C drive and make Unallocated space on the left with NIUBI Partition Editor. However, it also requires server rebooting, because the start position of system partition will be changed, too.

Steps to extend system reserved partition in Windows Server 2016 with NIUBI:

  1. Right click C: drive and select "Resize/Move Volume", drag left border towards right in the pop-up window, or enter an amount in the box of Unallocated space before directly.
  2. Right click the system reserved partition and select "Resize/Move Volume" again, drag right border towards right to combine Unallocated space.
  3. Click Apply to execute.

Video guide

  1. If there's not enough free space in C drive, you can shrink D or other data volume on the same disk. In that case, there's an additional step to move drive C towards right.
  2. If there's no available free space on the same disk, you can copy disk to a larger one and extend partition(s) with additional disk space.

How to increase system reserved partition in RAID/VMware/Hyper-V

If the system disk is any type of hardware RAID array built by several disks, do NOT break array or do any operations to raid controller, just follow the steps above, there's no difference. No matter how you built the raid array, the same disk mentioned above means Disk 0, 1, 2, etc. that shown by NIUBI Partition Editor.

If you run Windows Server 2016 as virtual machine in Hyper-V or VMware, you just need to install NIUBI to the virtual server and follow the steps above. There's only one difference, if there's no available free space in a virtual disk, you can expand it directly without copying to other disk. Follow the steps to expand VMware or Hyper-V disk.

There are many tools that have the ability to shrink partition and extend system reserved partition in Windows Server 2016, but comparing with other software, NIUBI Partition Editor is much safer and faster because of the innovative technologies:

It also helps you do many other disk and partition operations.

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