Convert a Single-Volume Storage Pool to a Multiple-Volume Storage Pool

You can add hard disks to a storage pool and convert the storage pool from one that supports only a single volume to one that supports multiple volumes. The original data on the single volume will not be affected.

To convert a single-volume storage pool to a multiple-volume storage pool:

Open Storage Manager.
Go to Storage Pool.
Select Convert to multiple volume support by adding hard disks from the Action drop-down menu.

Note:

This feature is supported on SHR storage pools only. SHR (Synology Hybrid RAID) is available on specific models only. For more information, please visit Synology website.
The number of added disks must increase the storage pool size; otherwise, you will not be able to perform the conversion.