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 DiskStation and later change to RAID 5 if you install more hard drives. This article provides instructions to change the RAID type of existing storage pools 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.

Note:

SHR (Synology Hybrid RAID) is available on specific models only. For more information, please visit Synology website.

Hard Drive Requirements

In order to change the RAID type of a storage pool, 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 storage pool to RAID 5, you'll need at least three hard drives in total (i.e. the two hard drives belonging to the RAID 1 storage pool, plus one free hard drive to add to the storage pool).

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 storage pool to a RAID 1 storage pool.

Before You Start:

Make sure the status of your storage pool is Normal.
When adding new hard drives to a storage pool, the new hard drives must be larger than the smallest hard drive in the storage pool.
The status of new hard 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 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-dowen menu.

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

Select which hard drive(s) 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 hard drive shall be deleted.