Change RAID Type of a Storage Pool
Storage pools can be changed from one RAID type to another without losing existing data. For example, you can create a RAID 1 storage pool on your Synology Unified Controller and later change to RAID 5 if you install more drives. This article provides instructions to change the RAID type of existing storage pools on your Synology Unified Controller.
RAID Type Limitations
Only some RAID types can be changed to other certain RAID types. See the table below for details.
| RAID type | Can be changed to… |
|---|---|
| Basic | RAID 1 RAID 5 |
| RAID 1 | RAID 5 |
Example:
RAID 1 can be changed to RAID 5, but RAID 5 cannot be changed to RAID 1.
Drive Requirements
In order to change the RAID type of a storage pool, you must have a sufficient number of available drives installed in your Synology Unified Controller. Please see below for the minimum number of drives required for each RAID type.
| Desired RAID type | Required number of drives |
|---|---|
| RAID 1 | 2 to 4 |
| RAID 5 | 3 |
| RAID 6 | 4 |
Example:
If you want to change a RAID 1 storage pool to RAID 5, you'll need at least three drives in total (i.e. the two drives belonging to the RAID 1 storage pool, plus one free drive to add to the storage pool).
Change RAID Type
In the example below, we will change a Basic storage pool to a RAID 1 storage pool.
Before You Start:
- Make sure the status of your storage pool is Normal.
- When adding new drives to a storage pool, the new drives must be larger than the smallest drive in the storage pool.
- The status of new drives must be Initialized or Not Initialized.
- The RAID type of RAID Arrays in RAID Groups cannot be changed. The RAID Group feature is available on specific models only. To see if your model supports the RAID Group feature, please refer to this article.
To change the RAID type of a storage pool:
- Open Storage Manager.
- Go to Storage Pool.
- Select the storage pool you wish to change and click Change RAID Type from the Action drop-down menu.
- Select the RAID type to which you want to change the storage pool. Click Next.
- Select which drive to add to the existing storage pool. Then click Next.
- Follow the instructions of the wizard to finish. Please note existing data on the added drive shall be deleted.
Note:
- With Secured SSD Cache, you can only choose SEDs.
- With Normal SSD Cache, you can only choose SEDs which are not protected by authentication.