In this article, we’re walking through the process for replacing a hard disk in a Synolgoy NAS. The NAS model for this walk-through is the “DS720+” running “DSM 7.2.2-72806 Update 5”. Our scenario is that we have 4TB of space in our RAID mirror, and we want to upgrade to 8TB. The process is as simple as replacing the first disk and allowing it to repair before doing the same for the second disk. In our case, there was no need to manually expand the volume to use the additional space – that happened automatically. The steps below reflect the above scenario. You should read the official Synology documentation when working such tasks. I have a link below that may be of use. The steps here are the steps I took but you should do your homework first.
- Open the Storage Manager.
- Select the disk to replace first. That might be Disk 1 or Disk 2 in a two disk NAS.
- Select Action and then Deactivate Drive. You’ll be asked to confirm this step.
The NAS will start beeping because the RAID is in a degraded state. You can stop the beeping or wait for the new disk to be detected and it will automatically stop beeping.
- Remove the disk that you have deactivated. On the NAS we’re using “DS720+”, we were able to do this without powering off the NAS. In other words, it supported hot-swapping.
- Insert the new disk in place of the removed disk. The Storage Manager should detect the new disk within a few seconds.
- Click the three-dot icon by the storage pool and select Repair.
- Select the replacement drive to add to the storage pool.
- Follow the wizard to finish.
In my case, the repair process took about 6 hours when repairing a 4TB volume.
Wait for the repair process to complete and then repeat that process for the second disk if needed.
You can find more details here: https://kb.synology.com/en-au/DSM/help/DSM/StorageManager/storage_pool_expand_replace_disk?version=7