Synology DiskStation DS1821+
High capacity storage and data protection for anyone

Overview:

Synology DiskStation DS1821+ is a powerful 8-bay network-attached-storage solution designed to store and protect missioncritical data. Designed to tackle increasing amounts of unstructured data, the low-noise desktop form-factor of the DS1821+ is built for both SOHO and SMB environments. With performance over 110K or 177% higher 4K random read IOPS than its predecessor, the DS1821+ is fast, with ample room for scalability.

• Accelerated Performance
  177% higher 4K random read IOPS and 76% faster sequential write speeds compared to its predecessor
• Maximize Performance
  Turbocharge HDD arrays by 20x or more without occupying drive bays using dual built-in M.2 slots for NVMe SSD cache
• Easy Expansion
  Scale-up on-demand to 18 drives with two DX517 expansion units
• Includes Everything to Protect Your Data
  Back up critical data to and from public clouds, Windows PCs and servers, virtual machines, and data on the NAS with Synology Active Backup suite, Hyper Backup, and Snapshot Replication
• Ready for 10GbE
  Add in a 10GbE SFP+ or RJ-45 NIC to instantly increase network bandwidth based on your existing infrastructure

Features:

Faster than ever

The DS1821+ can handle demanding application workloads and a greater number of concurrent users. Experience faster file indexing in Synology Drive, photo organization in Moments, and more responsive web services.

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Turbocharge and expand it

Upgrade your DS1621+ to match your data requirements, whether it is for faster networking or for higher storage capacity.

• 2 x M.2 NVMe
  Enable ultra-fast NVMe cache to accelerate HDD arrays by 20X or more
• 10GbE support
  Add in faster SFP+ or RJ-45 networking to turbocharge existing workflows
• Storage Expansion
  Supports two DX517 expansion units for a total of 18 bays

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Powered by Synology DiskStation Manager

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Specifications:

1. Status indicator
2. Alert indicator
3. Power button and indicator
4. LAN indicator
5. Drive status indicator
6. Drive tray
7. Drive tray lock
8. USB 3.2 Gen 1 port
9. Power port
10. System fan
11. PCIe expansion slot
12. Kensington Security Slot
13. Expansion port
14. 1GbE RJ-45 port
15. Reset button
16. USB 3.2 Gen 1 port

DiskStation DS1821+ Hardware Specifications:
Hardware Specifications
CPU	AMD Ryzen V1500B quad-core 2.2 GHz
Hardware encryption engine	Yes (AES-NI)
Memory	4 GB DDR4 ECC SODIMM (expandable up to 32 GB)
Compatible drive type	8 x 3.5" or 2.5" SATA HDD/SSD (drives not included) 2 x M.2 2280 NVMe SSD (drives not included)
Hot swappable drive	Yes
External port	4 x USB 3.2 Gen 1 2 x eSATA
Size (Height x Width x Depth)	166 x 343 x 243 mm
Weight	6.0 kg
LAN port	4 x 1GbE RJ-45
Wake on LAN/WAN	Yes
PCIe 3.0 slot	1 x 4-lane x8 slot Supports 10GbE network interface cards
Scheduled power on/of	Yes
System fan	2 (120 x 120 x 25 mm)
AC input power voltage	100 V to 240 V AC
Power Frequency	50 to 60Hz, single phase
Operating Temperature	0°C to 40°C (32°F to 104°F)
Storage Temperature	-20°C to 60°C (-5°F to 140°F)
Relative Humidity	5% to 95% RH
Maximum operating altitude	5,000 m (16,400 ft)
General DSM specification
Networking protocol	SMB, AFP, NFS, FTP, WebDAV, CalDAV, iSCSI, Telnet, SSH, SNMP, VPN (PPTP, OpenVPN, L2TP)
File system	Internal: Btrfs, ext4 External: Btrfs, ext4, ext3, FAT32, NTFS, HFS+, exFAT
Supported RAID type	Synology Hybrid RAID (SHR), Basic, JBOD, RAID 0, RAID 1, RAID 5, RAID 6, RAID 10
Storage management	Maximum single volume size: 108 TB Maximum system snapshots: 65,536 Maximum internal volume: 64
SSD cache	Read/write cache support M.2 NVMe SSD support
File sharing capability	Maximum local user account: 2,048 Maximum local group: 256 Maximum shared folder: 512 Maximum concurrent SMB/NFS/AFP/FTP connection: 1,000
Privilege	Windows Access Control List (ACL), application privileges
Directory service	Windows AD integration: Domain users login via SMB/NFS/AFP/FTP/File Station, LDAP integration
Virtualization	VMware vSphere 6.5, Microsoft Hyper-V, Citrix, OpenStack
Security	Firewall, shared folder encryption, SMB encryption, FTP over SSL/TLS, SFTP, rsync over SSH, login auto block, Let's Encrypt support, HTTPS (customizable cipher suite)
Supported client	Windows 7 onwards, macOS 10.12 onwards
Supported browser	Chrome, Firefox, Internet Explorer 11 onwards, Safari 11 onwards; Safari (iOS 11 onwards), Chrome (Android™ 6.0 onwards)
File Server & Synchronization
Drive	Provide a universal portal to synchronize your files across various platforms, including Windows, macOS, Linux, Android™ and iOS. The built-in universal portal allows you to access data anytime and anywhere. Maximum number of hosted files: 1,000,000 Maximum number of concurrent connections for PC clients: 550
File Station	Virtual drives, remote folders, Windows ACL editor, compressing/extracting archived files, bandwidth control for specific users/groups, creating sharing links, transfer logs
FTP Server	Bandwidth control for TCP connections, custom FTP passive port range, anonymous FTP, FTP SSL/TLS and SFTP protocol, boot over the network with TFTP and PXE support, transfer logs
Presto File Server	High-speed data transfer over WAN with exclusive SITA technology between Synology NAS and desktop
Cloud Sync	One or two-way synchronization with public cloud storage providers including Alibaba Cloud OSS, Amazon S3-compatible storage, Backblaze B2, Baidu Cloud, Box, Dropbox, Google Cloud Storage, Google Drive, hubiC, MegaDisk, Microsoft OneDrive, OpenStack Swift-compatible storage, Tencent COS, WebDAV servers, Yandex Disk
Universal Search	Offer global search into applications and files
File Server & Synchronization
iSCSI Manager	Maximum iSCSI target: 128 Maximum iSCSI LUN: 256 iSCSI LUN clone/snapshot support
Virtual Machine Manager	Deploy and run various virtual machines on Synology NAS, including Windows®, Linux®, or Virtual DSM
Data Protection & Backup Solution
Hyper Backup	Support local backup, network backup, and data backup to public clouds
Backup tools	DSM configuration backup, macOS® Time Machine® support, Synology Drive Client desktop application Shared folder sync - maximum task number: 16
Snapshot Replication	Maximum of shared folder snapshots: 1,024 Maximum of replication: 32
Synology High Availability	Reduce service downtime by setting up two identical NAS into one high-availability cluster
Active Backup for G Suite	Support G Suite My Drive and Team Drive backup and restoration
Active Backup for Microsoft 365	Supports Microsoft 365 OneDrive for Business, mail, contacts, and calendar backup and restoration
Active Backup for Business	All-in-one backup solution designed for heterogeneous business IT environment, enabling IT admins to remotely manage and monitor protection over PC, servers and VM on one centralized console
Productivity & Collaboration
Collaboration tools	Collaborate with instant message service Synology Chat, online editor Synology Office, and scheduling assistant Synology Calendar • Chat maximum user: 1,500 Office maximum user: 1,800 Calendar: support CalDAV and access via mobile devices
Note Station	Rich-text note organization and versioning, encryption, sharing, media embedding and attachments
Synology MailPlus Server	Secure, reliable, and private mail solution with high-availability, load balancing, security and filtering design (includes 5 free email account licenses; additional accounts require the purchasing of additional licenses)
Synology MailPlus	Intuitive webmail interface for Synology MailPlus Server, customizable mail labels, filters, and user interface
Multimedia
Moments	Support smart AI album with facial and subject recognition, photo editing and sharing features, similar photo detection, autoediting functions such as color correction and angle adjustments, and AI selection of the best photos. Mobile applications are available on iOS and Android™ devices
Other packages	Video Station, Photo Station, Audio Station, iTunes Server
Surveillance
Surveillance Station	Maximum IP camera: 40 (total of 1,200 FPS at 720p, H.264) (Including two free camera licenses. Additional cameras require the purchasing of additional licenses)
All-in-One Server
Synology Directory Server	Provide a flexible and cost-effective domain controller solution
Central Management System	Provide a single interface to manage and monitor multiple Synology NAS
VPN Server	Maximum connection: 30. Supported VPN protocol: PPTP, OpenVPN™, L2TP/IPSec
Mail Server	Supported Mail Server protocol: POP3, SMTP, IMAP. LDAP/AD account support
Mail Station	Webmail interface for Mail Server to receive emails from multiple POP3 mailboxes, customizable SMTP server
Web Station	Virtual host (up to 30 websites), PHP/MariaDB, 3rd-party applications support
Other packages	DNS Server, RADIUS Server, Log Center
Others
Storage Analyzer	Volume and quota usage, total size of files, volume usage and trends based on past usage, size of shared folders, large files, most recently modified files, least recently accessed files
Antivirus Essential	Full system scan, scheduled scan, white list customization, virus definition auto update
iOS/Android™ applications	Synology Drive, Synology MailPlus, Synology Chat, Synology LiveCam, Moments, DS audio, DS photo, DS video, DS cam, DS file, DS finder, DS note
Other packages	Additional 3rd-party packages available on Package Center
Certifications and Packaging
Environment safety	RoHS compliant
Package content	1 x DS1821+ main unit 1 x Quick Installation Guide 1 x Accessory pack 2 x Hard drive tray key 1 x AC power cord 2 x RJ-45 LAN cable
Optional accessories	DDR4 ECC SO-DIMM: D4ES01-4G/D4ES01-8G/D4ECSO-2666-16G 10GbE Network Interface Card: E10G18-T2/E10G18-T1/E10G17-F2 2.5" SATA SSD: SAT5200 M.2 2280 NVMe SSD: SNV3400 Expansion Unit: DX517 VisualStation: VS960HD/VS360HD Surveillance Device License Pack MailPlus License Pack Virtual DSM License Pack
Warranty	3 Years

Documentation:

Download the Synology DiskStation DS1821+ Datasheet  (PDF).