Resize/Extend RAID Partition in Windows Server 2016/2019/2022

by John, Updated on: July 27, 2022

Many servers are built in with hardware RAID array. For example, RAID 1 is used for operating system, RAID 5/10 is used for data storage. The same with single physical disk, system partition (C: drive) also runs out of space on RAID array. To solve this problem fast and easily, you'd better resize RAID partition with safe tool. Nobody likes to recreate partitions and restore everything from backup. In this article, I'll introduce how to resize/extend RAID partition in Windows Server 2016/2019/2022 without losing data.

How to resize RAID partition in Windows Server without any software

To Operating System and NIUBI Partition Editor, there's no difference if you use physical hard disk or hardware RAID array. In most cases, you can resize RAID partition in Windows Server 2016/2019/2022 the same with physical disk partition. No matter what the type of RAID and the brand of RAID controller is.

What you should concern is that whether there's free space in any partition on the same RAID array. The same array means Disk 0, 1, etc that are shown by Windows Disk Management or NIUBI Partition Editor. To most of servers, there's free space in one of the RAID virtual partitions. In that case, you can shrink it to extend other partition that is getting full. If there's no other virtual partition or the whole RAID array is full, it's more completed and I'll talk about in the last section. 

When there's free space on the same RAID array, you may try native Disk Management in Server 2016/2019/2022. It has Shrink Volume and Extend Volume functions to help resize NTFS partition without losing data. However, Disk Management is not the best tool because it has some restrictions.

The major shortage of Disk Management is that it can only resize NTFS partition, any other types of partitions are not supported. In addition, to NTFS partitions, Disk Management can only shrink it to create new volume. If you want to extend a partition by shrinking another one, Disk Management cannot help you. To extend/resize RAID partition in Server 2016/2019/2022, you'd better run safe partition software.

How to resize/extend RAID partition with safe partition software

In most of servers, there's plenty of free space in at least one of virtual partitions on the RAID array. You can shrink it to get Unallocated space and then add to other RAID partition that you want to expand. Open Windows Disk Management or NIUBI Partition Editor, you'll see if the partitions to be shrunk or extended are on the same RAID array. 

How to resize/extend RAID partition in Windows Server 2016/2019/2022:

  1. Download NIUBI Partition Editor, right click a NTFS or FAT32 partition and select "Resize/Move Volume". Drag either border towards the other one in the pop-up window, then you can shrink this partition. If you drag left border towards right or enter an amount in the box of Unallocated space before, Unallocated space will be made on the left of this partition.
  2. If you want to create new partition on this RAID, right click the Unallocated space and select "Create Volume". If you want to shrink D to extend C drive, make Unallocated space on the left when shrinking D drive. Then right click C:  drive and select "Resize/Move Volume" again, drag right border towards right in the pop-up window to combine this contiguous Unallocated space.
  3. Click Apply on top left to execute, done. (Any operations before this step only work in virtual mode.)

Video guide

  • If you want to shrink nonadjacent partition E to extend C, there's an additional step to move D to the right before adding Unallocated space to C drive.
  • No matter you use RAID 1/5/6/10, don't break RAID array or do any operations to RAID controller.

After resizing RAID partition in Windows Server 2016/2019/2022, operating system, programs and anything else (except partition size) keep the same with before.

How to expand RAID array without losing data

If there's no available free space on the same RAID array, what to do? It depends on how your RAID is configured.

To hardware RAID 1, you cannot increase size of this RAID by replacing with larger disks one by one and rebuilding the array. If you do like that, the RAID 1 will keep the same size. Additional space won't be shown by Disk Management or NIUBI Partition Editor, it can only be used to create another array with your RAID controller.

Steps to extend RAID 1 in Windows Server 2016/2019/2022 with larger disks:

  1. Build a new RAID 1 with 2 larger disks.
  2. Right click the front of original RAID 1 and select "Clone Disk".
  3. Select the new RAID 1 and click Next in the next window.
  4. Edit the size and location of the partitions in new RAID 1, starting from the last partition one by one.
  5. Click the option to turn off computer after clicking Apply to take effect.

Video guide

  • After copy complete, change BIOS to boot from the new RAID 1.
  • If you cannot attach 2 RAID at the same time, you may copy old RAID 1 to a physical disk, and then copy disk to the new RAID.
  • If your RAID controller can rebuild RAID 1 without losing data, you may clone old RAID 1 to a larger disk and extend partitions with extra disk space. After that, rebuild RAID 1 with another larger disk. 

To hardware RAID 5, you can increase its size easily. But before this, you'd better check the brand and model of your RAID controller, confirm it has the ability to rebuild RAID 5 without losing data. If yes, follow the steps to extend RAID 5 partition in Windows Server 2016/2019/2022:

  1. Replace with larger disks or add more same size disk and rebuild the array.
  2. Additional space will be shown as "Unallocated" at the end of original RAID array. Then  combine Unallocated space to the partition(s) that you want to expand.

Comparing with other tools, NIUBI Partition Editor is much safer and faster because of its Virtual Mode, Cancel-at-well, unique 1-Second Rollback technologies and advanced file-moving algorithm. Besides shrinking, extending and copy disk partitions, it helps move, merge, convert, defrag, hide, optimize, wipe partition, scan bad sectors and much more.