According to the Wikipedia, the RAID ("Redundant Array of Inexpensive Disks" or "Redundant Array of Independent Disks") is a data storage virtualization technology that combines multiple physical disk drive components into one or more logical units for the purposes of data redundancy, performance improvement, or both. Briefly, the RAID volumes make several disks work together to enhance overall system performance for computer users, especially the Server users.
However, sometimes you will need to expand RAID 0, RAID 1, or RAID 5 volumes. For example, when your current RAID volumes are almost full with data and you needs more storage space. To expand the RAID volume, you can add existing unallocated space into the RAID volume, or directly add a new drive to the RAID array. When there is not unallocated space on the current RAID array disks, you can add a new disk to the RAID array instead.
To add drive to RAID without losing data stored on the current RAID array, you can use Qiling Disk Master Server, which is compatible with all Windows Server and Windows PC. It has a "Dynamic Disk Manager" to help users to manage the dynamic disk and volumes easily, including adding a new drive to RAID array to increasing the capacity while preserving its existing data.
Note: To add a disk to the RAID array, you should convert the new disk to dynamic disk before proceeding.At the same time, the unallocated space on the disk should be equal or larger than the RAID volume on a single disk.