Synology DS1821+ Hardware Installation Manual page 15

To make sure your Synology NAS recognizes the new memory capacity
1 Install DiskStation Manager (DSM). Please see "Install DSM on Synology NAS" for more information.
2 Sign in to DSM as admin or a user belonging to the administrators group.
3 Go to Control Panel
If your Synology NAS does not recognize the memory or does not start up successfully, please make sure that
the memory module is installed correctly.
To remove the memory module
1 Follow step 1 to 3 of the "To install the memory module" section to shut down your Synology NAS,
disconnect the cables and remove the cover.
2 Push the levers on both sides of the memory module outward. The memory module will be released from its
slot.
3 Hold the memory module by its edges and remove it from the slot.
4 Replace the cover and tighten the two screws that removed.
5 Reconnect the cables that removed, then press the power button to turn on your Synology NAS.
15 Chapter 2: Hardware Setup
Info Center Total Physical
> and check
Memory.