Resize/Extend RAID Partition in Windows Server 2019

by John, Published on: March 16, 2020

This article introduces how to resize raid partition on Windows Server 2019, shrink and extend raid 1/5/10 partition on Server 2019 without losing data.

Hardware RAID array is common storage device in a server. There are many types of raid array such as raid 0, 1, 5, 6, 10. In general, raid 1 is used for Operating System, raid 5 is used for data only or data and OS. Hardware raid array has many advantages than single physical disk, but you won't find any difference in daily usage. You also need to create, format partition, shrink a large partition and extend the partition that is running out of space on a raid array. This article talks about how to resize raid partition in Windows Server 2019 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. The 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" hard disk in Disk Management and numbered the same with other disk. To both Operating System and programs, there's no difference between physical disk and raid virtual disk. They don't know whether a storage device is raid array or not.

Therefore, when resizing raid partition in Windows Server 2019, don't break raid array or do any operations to raid controller, simply follow steps below.

How to shrink and extend raid partition on Windows Server 2019?

The same with previous versions, Windows Server 2019 has 2 native tools - Disk Management and diskpart command tool, which 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.

It is much easier to resize raid partition on Server 2019 with third party software, however, you'd better make a backup and run safe partitioning software. Better than other tools, NIUBI Partition Editor is much safer and faster because of the advanced technologies:

Download NIUBI Partition Editor, you'll see all disks (physical and raid virtual) 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.

To shrink and extend raid partition in Windows Server 2019, 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 adjust raid partition when raid array is full?

In most cases, there's available free unused space on a raid array, so you can easily shrink the partition with plenty of free space and then extend the partition that is running out of space. But, if the raid array is almost full, it is more complicated than a single hard disk while extending raid partition in Windows Server 2019.

To hardware raid 1:

RAID 1 is built with 2 hard disks, you cannot increase raid 1 array by replacing with larger disk 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:

  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.

To hardware raid 5:

RAID 5 are built with at least 3 hard disk drives. When RAID 5 array is full, firstly check if your raid controller can expanding array by replacing with larger disks without losing data. If yes, follow the steps to extend raid 5 partition in Windows Server 2019:

  1. Replace disks with larger ones and rebuild the raid array one by one, then additional space will be shown as Unallocated on the end.
  2. 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.

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