Change RAID Type of a Volume or Disk Group

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.

RAID Type Limitations

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
SHR-1	SHR-2

Example:

RAID 1 can be changed to RAID 5, but RAID 5 cannot be changed to RAID 1.

Hard Drive Requirements

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
SHR-2	4 or 5 (depending on the disk constitution of SHR-1)

Example:

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).

Note:

SHR-1 with the following disk configurations may require two additional disks when changing to SHR-2:

There are only two disks.
All disks have different capacities.
Three or more disks in the RAID Array contain a pair of higher-capacity disks compared to the other disks in the RAID Array.

Change RAID Type

In the example below, we will change a Basic volume to a RAID 1 volume.

Before You Start:

Make sure the status of your volume or disk group is Normal.
When adding new hard drives to a volume or disk group, the new hard drives must be larger than the smallest hard drive in the volume or disk group.
The status of new hard drives must be Initialized or Not Initialized.

To change the RAID type of a volume:

Open Storage Manager.

Go to Volume. (If you want to change the RAID type of a disk group, then go to the Disk Group tab.)
Select the volume you wish to change and click Manage.

When the setup wizard appears, select Change RAID type. Then click Next.

Select the RAID type to which you want to change the volume. Click Next.

Select which hard drive(s) to add to the existing volume. Then click Next.

Follow the instructions of the wizard to finish. Please note existing data on the added hard drive shall be deleted.