Replace M.2 RAID 1 with larger drives

The following was tested on a DS1821+. It may not work on older models.

Note: Requires DSM 7.2 or later.

Replace NVMe RAID 1 drives in internal M.2 slots with larger drives.

1. Deactivate 1 of the NVMe drives (If one has died select it).
2. Shut down the Synology.
3. Replace the deactivated NVMe drive with a larger NVMe drive.
4. Boot the Synology.
5. Run Synology_HDD_db.
6. Open Storage Manager.
7. Click "repair now" on the M.2 storage pool and select the unused larger NVMe drive.
8. Wait for the repair to finish.
9. Repeat steps 1 to 8 for the NVMe drive(s) in the storage pool.
10. Change the volume size to use all of the available space:
    • Select the volume in Storage Manager > click ... > click Settings > click Max > click Save