Volumes and disk groups can be changed from one RAID type to another without losing existing data. For example, you can create a RAID 1 volume on your DiskStation, and later change to RAID 5 if you install more hard drives. This article provides instructions to change the RAID type of existing volumes and disk groups on your DiskStation.
Only some RAID types can be changed to certain other RAID types. See the table below for details.
| RAID type | Can be changed to… |
|---|---|
| Basic | RAID 1 RAID 5 |
| RAID 1 | RAID 5 |
| RAID 5 | RAID 6 |
RAID 1 can be changed to RAID 5, but RAID 5 cannot be changed to RAID 1.
In order to change the RAID type of a volume or disk group, you must have a sufficient number of available hard drives installed in your DiskStation. Please see below for the minimum number of hard drives required for each RAID type.
| Desired RAID type | Required hard drives |
|---|---|
| RAID 1 | 2 or 4 |
| RAID 5 | 3 |
| RAID 6 | 4 |
If you want to change a RAID 1 volume to RAID 5, you'll need at least three hard drives in total (i.e. the two hard drives belonging to the RAID 1 volume, plus one free hard drive to add to the volume).
In the example below, we will change a Basic volume to a RAID 1 volume.