Synology DS1821+ Manual

Synology NAS DS1821+
Hardware Installation Guide

Table of Contents
Chapter 1: Before You Start
Package Contents 3
Synology DS1821+ at a Glance 4
System Modes and LED Indicators 5
Other LED Indicators 7
Hardware Specication 8
Spare Parts 9
Optional Accessories 9
Safety Instructions 10
Chapter 2: Hardware Setup
Tools and Parts for Component Installation 11
Install Drives 11
Start Up Your Synology NAS 13
Add a Memory Module to Synology NAS 14
Add an M.2 NVMe SSD to Synology NAS 16
Add a Network Interface Card 17
Chapter 3: System Maintenance
Replace System Fan 18
Chapter 4: Install DSM on Synology NAS
Install DSM with Web Assistant 21
Learn More 21
2
Synology_HIG_DS1821+_20200828

Thank you for purchasing this Synology product! Before setting up your new Synology NAS, please check the
package contents to verify that you have received the items below. Also, make sure to read the safety instructions
carefully to avoid harming yourself or damaging your Synology NAS.
Note: All images below are for illustrative purposes only, and may di󰀨er from the actual product.
Package Contents
Main unit x 1 AC power cord x 1
RJ-45 LAN cable x 2
Hard drive tray key x 2
Screws for 2.5" drives x 36
Before You Start 1
Chapter
3

4Chapter 1: Before You Start
Synology DS1821+ at a Glance
No. Article Name Location Description
1STATUS Indicator
Front
Displays the status of the system. For more information, see
"System Modes and LED Indicators".
2ALERT Indicator Displays warnings regarding fan or temperature. For more
information, see "Other LED Indicators".
3POWER Button
1. Press to power on your Synology NAS.
2. To power o󰀨 your Synology NAS, press and hold until you
hear a beep sound and the Power LED starts blinking.
4LAN Indicator Displays the status of the network connection. For more
information, see "Other LED Indicators".
5DRIVE Status Indicator Displays the status of each drive. For more information, see
"Other LED Indicators".
6Drive Tray Install drives (hard disk drives or solid state drives) here.
7Drive Tray Lock Lock or unlock drive trays.
8USB 3.2 Gen 1 Port Connect external drives or other USB devices to the Synology
NAS here.
9Power Port
Rear
Connect power cord here.
10 Fan Disposes of excess heat and cools the system. If the fan
malfunctions, the Synology NAS will emit a beeping sound.
11 PCI Express
Expansion Slot Supports the addition of PCIe network interface cards.
12 Kensington Security Slot Attach a Kensington security lock here.
13 eSATA Port 1 Connect Synology Expansion Unit1to the Synology NAS here.
14 LAN Port Connect RJ-45 network cable here.
15 RESET Button
1. Press and hold until you hear a beep sound to restore
the IP address, DNS server, and password for the admin
account to default.
2. Press and hold until you hear a beep, then press and hold
again until you hear three beeps to return the Synology
NAS to "Not Installed" status so that DiskStation Manager
(DSM) can be reinstalled.
16 USB 3.2 Gen 1 Port Connect external drives or other USB devices to the Synology
NAS here.
17 eSATA Port 2 Connect Synology Expansion Unit1to the Synology NAS here.
6 7
19
16138171512
11
14
10
3 4 5 2
1For more information about Synology Expansion Unit supported by your Synology NAS, please visit www.synology.com.

5Chapter 1: Before You Start
System Modes and LED Indicators
System Modes and Denitions
There are 7 system modes in Synology NAS. The System modes and their denitions are as below:
System mode Denition
Powering on Synology NAS is powering on and performing hardware initialization, such as
hardware reset or BIOS initialization.
Shutting down Synology NAS is shutting down as a result of pressing the power button or operation
in DSM.
DSM not ready
DSM is not ready for use. This could either be:
• Synology NAS is powered on, but DSM is not properly installed.
• Synology NAS is currently powering on and initializing services necessary for
DSM to fully function.
•The attached UPS device has insu󰀨icient power; DSM stops all services to
prevent data loss (enters safe mode).
DSM is ready for use DSM is fully functioning and users can sign in.
Hibernation Synology NAS has been idle for a while and is now in Hibernation mode.
Application
Certain packages/services (e.g., USB Copy and Find me service) while in operation
will control the actions of the LED. After the operation is complete, the LED indicator
will return to its normal state.
Powered o󰀨 Synology NAS is powered o󰀨.
Identify System Modes
You can identify the system mode through the POWER and STATUS LED indicators. Please refer to below table
for more details.
System mode
LED Indicator
POWER STATUS
Blue Green Orange
Powering on Blinking O󰀨 O󰀨
Shutting down Blinking Static O󰀨
DSM not ready Static Blinking O󰀨
DSM is ready for use Static Static O󰀨
Hibernation Static O󰀨 O󰀨
Application Static Switching
Powered o󰀨 O󰀨 O󰀨 O󰀨

6Chapter 1: Before You Start
Transitions between System Modes
To better understand the transition between system modes, please refer to below examples:
•Powered on with no DSM installed:
Powered off > Powering on > DSM not ready
•Powered on with DSM installed:
Powered off > Powering on > DSM not ready > DSM is ready for use
•Enter hibernation then wake up from hibernation:
DSM is ready for use > Hibernation > DSM is ready for use
•Shutdown Synology NAS:
DSM is ready for use > Shutting down > Powered o󰀨
•Power failure with UPS attached:
DSM is ready for use > DSM not ready (due to power failure, DSM enters safe mode) > Shutting down >
Powered off > Powering on (power has recovered, DSM will reboot)> DSM not ready > DSM is ready for use

7Chapter 1: Before You Start
Other LED Indicators
LED Indicator Color Status Description
DRIVE status
Green
Static Drive ready and idle
Blinking Accessing drive
Orange Static Drive error/Port disabled1
O󰀨 No internal Drive
ALERT
Orange Blinking System error2
O󰀨 System normal
LAN
Green
Static Network connected
Blinking Network active
O󰀨 No network
Rear 1GbE LAN
(on left side of jack)
Green
Static Network connected
Blinking Network active
O󰀨 No network
Rear 1GbE LAN
(on right side of jack)
Green
Static
1 Gbps connected
Orange 100 Mbps connected
O󰀨 10 Mbps connected/No network
Note:
1 Please try to restart your Synology NAS or re-insert the drives, then run the HDD/SSD manufacturer's
diagnostic tool to check the health status of the drives. If you can sign in to DSM, please run the built-in
S.M.A.R.T. test to scan the drives. If the problem remains unresolved, please contact Synology Technical
Support for help.
2 If the ALERT LED continuously blinks orange, this indicates there are system errors such as fan failure,
system overheating, or volume degrade. Please sign in to DSM for detailed information.

8Chapter 1: Before You Start
Hardware Specication
Item DS1821+
Compatible Drive Type • 3.5” / 2.5” SATA x 8
• M.2 2280 NVMe SSD x 2
Maximum Internal Raw Capacity • 128TB (8 x 16TB HDD)
• 288 TB with 2 x DX517 (expansion unit)
External Port •USB 3.2 Gen 1 x 4
• eSATA x 2
LAN Port 1GbE (RJ-45) x 4
PCIe Slot Gen3 x8 slot (x4 link) x 1
Size (H x W x D) (mm) 166 x 343 x 243
Weight (kg) 6.0
Supported Client • Windows 7 onwards
• macOS 10.12 onwards
File System • Internal: Btrfs, ext4
• External: Btrfs, ext4, ext3, FAT32, NTFS, HFS+, exFAT1
Supported RAID Type • Basic • JBOD • RAID 0 • RAID 1
• RAID 5 • RAID 6 • RAID 10
Agency Certication • FCC Class B • CE Class B • BSMI Class B
• EAC • VCCI • CCC • RCM • RoHS Compliant
HDD Hibernation Yes
Scheduled Power On/O󰀨 Yes
Wake on LAN Yes
Language Localization
Environment Requirement
• Line voltage: 100 V to 240 V AC
• Frequency: 50/60 Hz
•Operating Temperature: 32 to 104˚F (0 to 40˚C)
•Storage Temperature: -5 to 140˚F (-20 to 60˚C)
• Relative Humidity: 5% to 95% RH
Note: Model specications are subject to change without notice. Please refer to www.synology.com for the latest information.
1Support for exFAT can be enabled by purchasing and downloading exFAT Access in Package Center.

9Chapter 1: Before You Start
Spare Parts
Visit www.synology.com/products/spare_parts if you need to replace system fans, disk trays, or power supply
units.
Model Name Picture Description
Disk Tray (Type D6) 3.5"/2.5" Drive Tray With Lock
Fan 120*25_5 System Fan 120*120*25 mm
PSU 250W_5 PSU 250W 24p+12p+8p
Optional Accessories
With Synology accessories, you can customize your Synology NAS to t di󰀨erent business environments without
worrying about compatibility and stability. Visit www.synology.com/compatibility for more information.

10 Chapter 1: Before You Start
Safety Instructions
Keep away from direct sunlight and from chemicals. Make sure the environment does not experience
abrupt changes in temperature or humidity.
Place the product right side up at all times.
Do not place near any liquids.
Before cleaning, unplug the power cord. Wipe with damp paper towels. Do not use chemical or
aerosol cleaners.
To prevent the unit from falling over, do not place on carts or any unstable surfaces.
The power cord must plug in to the correct supply voltage. Make sure that the supplied AC voltage is
correct and stable.
To remove all electric current from the device, ensure that all power cords are disconnected from the
power source.
Risk of explosion if battery is replaced with an incorrect type. Dispose of used batteries appropriately.

11
Tools and Parts for Component Installation
Please prepare the following tools and parts before setting up your Synology NAS:
• A screwdriver (only for 2.5" drives)
• At least one 3.5" or 2.5" SATA drive (please visit www.synology.com/compatibility for compatible drive
models)
Warning: If you install a drive that contains data, the system will format the drive and erase all existing data.
Please back up any important data before installation.
Install Drives
1 Press the lower part of the hard drive tray to unlock the handle.
DS1821+
2 Pull out the hard drive tray handle as shown below to remove the hard drive tray.
DS1821+
3 Load drives in the drive trays.
• For 3.5" drives: Remove the fastening panels from the sides of the drive tray. Place the drive in the drive
tray. Then insert the fastening panels to secure the drive in place.
Hardware Setup 2
Chapter

12 Chapter 2: Hardware Setup
• For 2.5" drives: Remove the fastening panels from the sides of the drive tray and store them in a safe
place. Place the drive in the area of the drive tray indicated by a blue rectangle below. Turn the tray upside
down and tighten the screws to secure the drive in place.
4 Insert the loaded hard drive tray into the empty hard drive bay and push it into position by the upper half of the
handle.
DS1821+
Note: Make sure that the drive tray is completely inserted. Otherwise, the drive might not function properly.
5 Press the handle back into the front panel until you hear a click to secure the hard drive tray in place.
6 Insert the hard drive tray key into the hard drive tray lock, turn the key clockwise (to the "I" position) to lock the
hard drive tray handle, and then remove the key.

13 Chapter 2: Hardware Setup
7 Repeat the steps above to install the other drives you have prepared.
8 Drives are numbered as shown below.
1 2 3 4 65 87
Note: If you plan to create a RAID volume, we recommend installing drives of identical size to make the best
use of drive capacity.
Start Up Your Synology NAS
1 Use the LAN cable to connect the Synology NAS to your switch, router, or hub.
2 Connect one end of the AC power cord to the power port of your Synology NAS. Connect the other end to a
power outlet.
1
2
3 Press the power button to turn on your Synology NAS.
DS1821+
Congratulations! Your Synology NAS is now online and detectable from a network computer.

14 Chapter 2: Hardware Setup
Add a Memory Module to Synology NAS
Optional Synology memory modules are designed to expand the memory of your Synology NAS. Follow the steps
below to install, check, or remove a memory module on your Synology NAS.
The following table shows the memory conguration for best practice:
A0 B0 Total Memory
4 GB - 4 GB
4 GB 4 GB 8 GB
8 GB 8 GB 16 GB
16 GB 16 GB 32 GB
Follow the steps below to install, check, or remove a memory module on your DS1821+.
To install the memory module
1 Shut down your Synology NAS. Disconnect all cables from your Synology NAS to prevent possible damage.
2 The memory modules are located at the bottom of your Synology NAS.
3 Remove the two screws on the cover that protecting the modules. Lift up the cover and put it aside. You will
see one pre-installed 4 GB memory module.
A0
B0
Note: When you remove the cover, sensitive internal components are exposed. Avoid touching anything other
than the memory assembly when removing or adding memory.
4 Insert the new memory module into the empty slot:
a Align the small gap between the gold connectors of the memory module with the notch on the empty slot.
Insert the memory module into the slot. Make sure that the module is properly inserted.
b Gently push down the memory module until you hear a click.
Note:
• Hold the memory module by its edges and avoid touching the gold connectors.
• Synology will not provide full product warranty or technical support if a non-Synology memory module is
used for memory upgrade.
5 Replace the cover and tighten the two screws that removed.
6 Reconnect the cables that removed, then press the power button to turn on your Synology NAS.

15 Chapter 2: Hardware Setup
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 > Info Center and check Total Physical Memory.
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.

16 Chapter 2: Hardware Setup
Add an M.2 NVMe SSD to Synology NAS
You can install up to two M.2 NVMe 2280 SSDs on your Synology NAS to create an SSD cache volume. Follow
the steps below for SSD module installation and removal.
To install an M.2 NVMe SSD module
1 Shut down your Synology NAS. Disconnect all cables from your Synology NAS to prevent possible damage.
2 Remove the hard drive trays from the drive bays. You will see two empty SSD slots located on the inner left
side of your Synology NAS.
3 SSD slots are numbered as shown below.
1
2
Note: Hold the SSD module by its edge and avoid touching the gold connectors.
4 Start from the slot 1. Insert your SSD module into the empty slot:
a Align the small gap between the gold connectors of the SSD module with the notch in the empty slot. Insert
the module into the slot. Make sure that the module is properly inserted.
b Push the lever outward as shown below. While holding the lever, push down the SSD module, then release
the lever to secure the SSD module.
ab
5 If needed, repeat the steps above to install a second SSD module into the second slot.
6 Insert the drive trays back into the drive bays.
7 Reconnect the cables removed in step 1, then press the power button to turn on your Synology NAS.
To remove the M.2 NVMe SSD module
1 Shut down your Synology NAS. Disconnect all cables from your Synology NAS to prevent possible damage.
2 Remove the hard drive trays from the drive bays.
3 Push the lever outward. The module will pop up and be released from the slot.
4 Hold the SSD module and remove it from the slot. Insert the drive trays back into the drive bays.
5 Reconnect the cables removed in step 1, then press the power button to turn on your Synology NAS.

17 Chapter 2: Hardware Setup
Add a Network Interface Card
Your Synology NAS has a PCI Express expansion slot which allows you to install 10GbE or Gigabit network
interface card for LAN port expansion.
To install a network interface card:
1 Shut down your Synology NAS. Disconnect all cables from your Synology NAS to prevent possible damage.
2 Remove the six screws that secure the top cover.
3 Install the network interface card:
a Remove the screw that secures the adapter slot’s cover.
b Remove the adapter slot’s cover.
ab
c Align the card’s connectors with the adapter slot, and insert the card into the slot.
d Put back and fasten the screw that you removed in step 3-a so as to secure the newly inserted card.
cd
4 Put back the top cover that you removed in step 2 and tighten the srcews.
Note: Make sure the connectors are fully inserted. Otherwise, the network interface card might not be able to
function properly.

18
3
Chapter
System Maintenance
Replace System Fan
If the cooling fan located on the back of the Synology NAS malfunctions, please follow the steps below to remove
the malfunctioning fan and replace it with a new one.
1 Power o󰀨 your Synology NAS and remove the power cord.
2 Fans are numbered as shown below:
12
3 Remove the four screws that secure the fan panel.
4 Remove the malfunctioning fan:
a Pull out the fan panel from your Synology NAS.
b Carefully unplug the power cords located at the bottom of the fan socket as shown below.

19 Chapter 3: System Maintenance
c Remove the screws that secure the fan from the fan case.
d Remove the screws that secure the fan guard from the malfunctioning fan.
5 Install a new fan:
a Attach the fan guard to the new fan, then tighten the screws to secure the fan guard.

20 Chapter 3: System Maintenance
b Attach the fan case (with the fan cable within the fan pointing at the bottom-right corner) to the new fan, then
tighten the screws to secure the fan case.
c Plug the fan cables into your Synology NAS as shown below.
12
6 Replace and tighten the four screws removed in step 3.