Replace Drives to Expand Storage Capacity

When using certain RAID types, you can expand the storage capacity of a storage pool by replacing old drives with ones of larger size. This article provides important information regarding the expansion process, as well as an example of how to replace existing drives in order to expand storage capacity.

Note:

If you plan on replacing multiple drives, you must be careful to replace drives one-by-one. After replacing one drive, you must repair the storage pool before replacing the next one. For the following RAID types, storage pool capacity will expand once all drives have been replaced: RAID 1, RAID 5, RAID 6, RAID 10, RAID F1.

Before You Start

Before replacing a drive, please see the following notes:

SHR (Synology Hybrid RAID)

Because SHR storage pools optimize storage capacity based on the number and size of installed drives, please follow the following guidelines in order to properly expand capacity:

RAID 5 / RAID 6 / RAID 10 / RAID F1

When replacing drives of RAID 5 / RAID 6 / RAID 10 / RAID F1 storage pools, the smallest drive should always be replaced first in order to maximize drive usage. The storage capacity of each RAID type is as follows:

For example, if your RAID 5 storage pool contains three drives that are 4 TB, 3 TB, and 2 TB, respectively, the available capacity of your storage pool will be 4 TB. If you replace the 4 TB drive or the 3 TB drive, the capacity of the storage pool will not change. To increase the capacity of your storage pool, the 2 TB drive must be replaced first.

Replace Drive to Expand Storage Capacity

In the steps below, we will provide an example of replacing the drives of an SHR storage pool.

To replace drives:

  1. Launch Storage Manager.
  2. Go to Storage Pool to see which existing drive is the smallest.
  3. Power off your DiskStation. (Skip this step if your DiskStation supports hot-swapping.)
  4. Remove the smallest of the member drives and install a new, larger drive.
    Note: To avoid harming yourself or damaging your DiskStation, please follow the drive installation instructions found in the Hardware Installation Guide for your Synology product.
  5. Power on your DiskStation.
  6. Launch Storage Manager again.
  7. Go to HDD/SSD to make sure the new drive is recognized.
  8. The status of your storage pool should be Degraded. Select the storage pool, click Repair from the Action drop-down menu.
  9. Select the replacement drive to add to the storage pool. Then follow the steps of the wizard to finish.
  10. Repeat the above process until all desired drives have been replaced with larger ones.