Resize/Extend RAID Partition in Windows Server 2019/2022

by John, Updated on: August 10, 2022

Hardware RAID array is common storage device in a server. In most of servers, RAID 1 is used for operating system and programs, RAID 5 is used for saving data. Hardware RAID has many advantages than single physical disk, but you won't find any difference in daily usage. Before saving files to a RAID array, you also need to initialize, create and format partition. The same with physical disk, you also need to shrink a large RAID partition to create new volume or extend another RAID partition that is getting full. This article introduces how to resize RAID partition in Windows Server 2019/2022 without losing data.

Any difference while resizing RAID partition and physical drive?

Many people think it is complicated to resize virtual partition on a RAID array, but it's not. Hardware RAID arrays are built with 2 or more physical hard disk drives, the advantages are realized by RAID card/controller. After building the RAID array, you get a "virtual" disk in Disk Management and it's numbered the same with other disk. To both operating system and NIUBI Partition Editor, there's no difference if you use single SSD, mechanical HDD or RAID array. Better than Windows Disk Management and other disk partition software, NIUBI Partition Editor shows the model of all storage device on the main window. So you'll see clearly the interface (SATA, SCSI, USB, NVme, etc.) of a single disk, RAID array will be marked, too.

When you resize RAID partition in Windows Server 2019/2022 and other versions, don't break RAID array or do any operations to RAID controller, follow steps below.

How to resize RAID partition in Windows Server 2019/2022

The same with previous versions, Windows Server 2019/2022 has 2 native tools - Disk Management and diskpart command tool. Both tools can shrink and extend partition without losing data (in most cases). However, they cannot extend a partition by shrinking another one. To be accurate, they can only shrink NTFS partition to create new volume, or extend a NTFS partition by deleting the contiguous partition on the right.

To resize RAID 1/5/10 partition in Windows Server 2019/2022, third party software is more powerful. However, you'd better make a backup in advance and run safe partitioning software. Better than other tools, NIUBI Partition Editor is much safer and faster because of advanced technologies:

Download NIUBI Partition Editor, you'll see all storage devices with partition structure and other detailed information. Available operations to selected disk or partition are listed on the left and by right clicking, unavailable operations are hidden automatically.

In most cases, there's free space in other virtual partition on the same RAID array. To shrink and extend RAID partition in Windows Server 2019/2022, you just need to drag and drop on the disk map. Follow the steps in the video.

How to extend system partition C by shrinking data volume:

Video Server 2019

How to extend a data partition by shrinking another one:

Video Server 2019

How to extend RAID 1/5 partition when RAID array is full

If the RAID array is almost full, it is more complicated than a single hard disk while extending RAID partition in Windows Server 2019/2022.

To hardware RAID 1:

RAID 1 is built with 2 hard disks, you cannot increase RAID 1 array by replacing with larger disks one by one. If you do like that, you'll get another RAID 1 with same size, the remaining space will be wasted or used to create another RAID array.

To extend RAID 1 partition in Windows Server 2019/2022:

  1. Build a new RAID 1 with 2 larger disk.
  2. Follow the method in the video to copy original RAID 1 to the new one.
  3. Change BIOS settings and boot from this new RAID 1.

If you cannot connect 2 RAID 1 to the server at the same, follow the steps:

  1. Insert a single hard disk to this server.
  2. Copy original RAID 1 to this disk (there's no difference to copy between RAID array and single disk).
  3. Change BIOS settings and boot from the single hard disk.
  4. Build a new RAID 1 and copy from this disk.
  5. Boot from the new RAID 1.

If your RAID controller has the ability to rebuild RAID 1 without losing data, it's much easier, follow the steps:

  1. Copy original RAID 1 to one of the larger disks, remember to extend partitions with extra space.
  2. Rebuild RAID 1 with the other larger disk.

To hardware RAID 5:

RAID 5 are built with at least 3 hard disk drives. When RAID 5 array is full, firstly make sure your RAID controller can rebuild array without losing data. If yes, to extend RAID 5 array in Windows Server 2019/2022, you may either add new disk or replace disks with larger ones. After rebuilding array, additional space is shown as "Unallocated" at the end of RAID. Then follow the steps to move and merge Unallocated space to other partition(s).

Besides shrinking, extending, moving and copying disk partitions, NIUBI Partition Editor helps do many other disk partition operations.