High-performance storage for data protection, file serving, and more.
Versatile and scalable storage
Synology RS2821RP+ is a 3U 16-bay storage server designed to accommodate a diverse set of business requirements. Scalable to 28 drives, the unit provides powerful backup and restoration functionality for the SMB sector. It delivers 2,200 MB/s sequential read and 105K 4K random read performance1, and can be upgraded with SSD cache and 10/25Gb Ethernet2 options.
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- Compute : AMD Ryzen™ V1500B quad-core 2.2 GHz
- Throughput : 2,220 MB/s seq. read 105K 4K random read performance
- Memory : 4 GB ECC DDR4, up to 32 GB
- Scalability : Up to 28 drive bays with RX1217(RP)
High performance storage for anything
Over 105K/59K random read/write IOPS and up to 2,220/1,164 MB/s sequential read/write throughput ensure ample performance for demanding workloads.
Built for reliability
Reduce the possibility of power disruptions on a single distribution channel or PDU adversely impacting data and service availability.
Pair two identical devices with Synology High Availability and enable automatic minute-level failover between both devices in the event one server fails. Learn more
Data integrity and protection
ECC memory brings higher system reliability, while the Btrfs file system helps prevent data corruption, supports snapshot technology, and simplifies data protection. Learn more
Customize to suit
Easily adapt the RS2421+/RS2421RP+ to any business environment by adding faster networking, local SSD cache, or storage capacity.2
Support for 10/25GbE NICs lets you boost maximum network throughput using Link Aggregation (bonding).
Boost read/write IOPS over HDD-only arrays by up to 16 times or more with NVMe or SATA SSD Cache
On-demand drive bays
Expand to 28 drive bays with one RX1217(RP) expansion unit
License-free backup solutions
Back up your NAS to other devices
Back up files, iSCSI LUNs, installed applications, and system configurations to destinations including Synology C2 Storage, public cloud platforms, USB devices, file servers, local folders, or other Synology NAS.
Set and forget backup tasks with regular schedules, enhance security with fine-grained user permissions and encryption, keep backup sizes small with built-in deduplication5, and restore data flexibly with multi-versioning. Learn more
Snapshot Replication enables flexible point-in-time snapshots of shared folders and virtual machines with an RPO as low as 5 minutes and recovery within seconds. Learn more
Consolidate backups to your NAS
Active Backup Suite
Securely back up Windows clients and servers, Microsoft 365 and Google Workspace accounts, file servers, and VMware and Hyper-V virtual machines with the Active Backup Suite.
Leverage built-in deduplication6 technology to reduce backup sizes and multi-versioning to allow flexible restoration. Learn more
Serving remote workforces
Keep your remote workforce connected with powerful out-of-the-box solutions for collaboration, file sharing, and communication.
Host your own private cloud behind the safety of your NAS with 100% data ownership and no subscription fees.
Create documents, spreadsheets, and slides in a multi-user environment. Real-time collaboration and automatic saving make remote work sessions a breeze.
Discuss and collaborate with colleagues using secure messaging designed for teams, with mobile, desktop, and browser clients.
Storage for virtualization
DSM streamlines provisioning for and management of virtual machines with full certification for VMware® vSphere™, Microsoft® Hyper-V®, Citrix® XenServer™, and OpenStack virtualization environments.
Synology Storage Console for VMware or Windows platforms lets you manage storage directly from your hypervisor. VMware VAAI integration and Windows ODX help offload storage operations and speed up data transfer. Learn more
Works best with Synology drives
Engineered to handle intensive 24/7 workloads, Synology drives consistently deliver top-grade performance.
Powered by Synology DiskStation Manager
The web-based DiskStation Manager (DSM) operating system supports a host of native productivity and management solutions.
Central Management System
Conveniently manage your fleet of Synology NAS from a centralized console.
Instantly access your NAS files across multiple devices whenever you want, wherever you are.
Satisfy all team collaboration needs behind the safety of your own private cloud with Synology Office, Calendar, and Chat.
Virtual Machine Manager
Run various operating systems in isolated sandboxes. Seamlessly clone, store, and migrate virtual machines.
Secure data with comprehensive built-in security tools to protect your devices against evolving threats.
Complete surveillance solution for recording, monitoring, and management.
|CPU Model||AMD Ryzen V1500B|
|CPU Frequency||4-core 2.2 GHz|
|Hardware Encryption Engine (AES-NI)|
|System Memory||4 GB DDR4 ECC UDIMM|
|Memory Module Pre-installed||4 GB (4 GB x 1)|
|Total Memory Slots||2|
|Maximum Memory Capacity||32 GB (16 GB x 2)|
|Maximum Drive Bays with Expansion Unit||28 (RX1217/RX1217RP x 1)|
|Compatible Drive Type* (See all supported drives)||
|Hot Swappable Drive*|
|RJ-45 1GbE LAN Port||4 (with Link Aggregation / Failover support)|
|USB 3.2 Gen 1 Port*||2|
|Notes||The USB 3.0 standard was renamed to USB 3.2 Gen 1 by the USB Implementers Forum (USB-IF) in 2019.|
|PCIe Expansion||1 x Gen3 x8 slot (x4 link)|
|Notes||exFAT Access can be installed for free from Package Center in DSM 7.0. In DSM 6.2 or earlier versions, exFAT Access needs to be purchased in Package Center.|
|Form Factor (RU)||3U|
|Size (Height x Width x Depth)||132.3 mm x 482 mm x 656.5 mm|
|Rack Installation Support*||4-post 19" rack (Synology Rail Kit – RKS-02)|
|Notes||The rail kit is sold separately|
|System Fan||80 mm x 80 mm x 3 pcs|
|Fan Speed Mode||
|Easy Replacement System Fan|
|Noise Level*||53.5 dB(A)|
|Scheduled Power On / Off|
|Wake on LAN / WAN|
|Power Supply Unit / Adapter||550 W|
|Redundant Power Supply|
|AC Input Power Voltage||100 V to 240 V AC|
|Power Frequency||50/60 Hz, Single Phase|
97.54 W (Access)
49.57 W (HDD Hibernation)
|British Thermal Unit||
332.61 BTU/hr (Access)
169.03 BTU/hr (HDD Hibernation)
|Operating Temperature||0°C to 35°C (32°F to 95°F)|
|Storage Temperature||-20°C to 60°C (-5°F to 140°F)|
|Relative Humidity||5% to 95% RH|
|3-year hardware warranty, extendable to 5 years with EW202 or Extended Warranty Plus|
|Notes||All memory modules will operate at the maximum frequency specified by the CPU manufacturer.|
|Maximum Single Volume Size*||108 TB|
|Maximum Internal Volume Number||64|
|SSD Read / Write Cache (White Paper)|
|Supported RAID Type||
|Volume Expansion with Larger HDDs||
|Volume Expansion by Adding a HDD||
|Global Hot Spare Supported RAID Type||
|Maximum Concurrent SMB/AFP/FTP Connections||1,000|
|Maximum Concurrent SMB/AFP/FTP Connections (with RAM expansion)||2,000|
|Windows Access Control List (ACL) Integration|
|NFS Kerberos Authentication|
|Maximum Local User Accounts||2,048|
|Maximum Local Groups||256|
|Maximum Shared Folder||512|
|Maximum Shared Folder Sync Tasks||16|
|Maximum Hybrid Share Folders||10|
|Synology High Availability|
|Syslog Events per Second||1,000|
|VMware vSphere with VAAI|
|Networking Protocols||SMB1 (CIFS), SMB2, SMB3, NFSv3, NFSv4, NFSv4.1, NFS Kerberized sessions, iSCSI, HTTP, HTTPs, FTP, SNMP, LDAP, CalDAV|
|Supported Language||English, Deutsch, Français, Italiano, Español, Dansk, Norsk, Svenska, Nederlands, Русский, Polski, Magyar, Português do Brasil, Português Europeu, Türkçe, Český, ภาษาไทย, 日本語, 한국어, 繁體中文, 简体中文|
|Notes||For an updated list of supported browser versions, check the DSM Technical Specifications.|
Add-on Packages view the complete package list
Antivirus by McAfee (Trial)
|Maximum Number of Concurrent Users||150|
|Notes||When applicable, systems are tested configured with maximum memory and set to allow the maximum number of connections.|
|Maximum Concurrent Download Tasks||80|
|Maximum iSCSI Target Number||128|
|LUN Clone/Snapshot, Windows ODX|
|Notes||iSCSI Manager has been renamed to SAN Manager in DSM 7.0.|
|Free Email Accounts||5 (Licenses required for additional accounts)|
|Maximum Number of Concurrent Users||150|
|Maximum Server Performance||1,484,000 emails per day, approx. 45GB|
|Maximum Snapshots per Shared Folder||1,024|
|Maximum of System Snapshots||65,536|
|Maximum IP cam (Licenses required)||40 (including 2 Free License) (see all supported IP cameras)|
|Total FPS (H.264)||
1200 FPS @ 720p (1280×720)
1050 FPS @ 1080p (1920×1080)
600 FPS @ 3M (2048×1536)
440 FPS @ 5M (2591×1944)
320 FPS @ 4K (3840×2160)
|Total FPS (H.265)||
1200 FPS @ 720p (1280×720)
1200 FPS @ 1080p (1920×1080)
1120 FPS @ 3M (2048×1536)
600 FPS @ 5M (2591×1944)
480 FPS @ 4K (3840×2160)
|Recommended Number of Concurrent Sync Clients||550 (the number of connections that can be maintained when the recommended number of hosted files was reached)|
|Recommended Number of Hosted Files||50,000,000 (applies to files indexed or hosted by Synology Drive. For file access through other standard protocols, refer to the File Services section above)|
|Recommended Virtual Machine Instances||8 (Learn more)|
|Recommended Virtual DSM Number (Licenses required)||8 (including 1 Free License)|
|Notes||The specifications vary depending on system configuration and memory size.|
- Model specifications are subject to change without prior notice.
- The figures are based on Synology internal testing. Each performance test is done individually. No other services or applications are processed at the same time.
- The actual performance may be lower than lab testing figure due to differences in server configuration, deployment, and the number of active operations.
- If usage requirements exceed the specifications above, please contact our regional partners for professional advice.