Secure storage for your business

Synology RS2421+/RS2421RP+ are versatile 2U 12-bay storage servers designed to accommodate a diverse set of business environments. Scalable up to 24 drives, they are designed for cost-effective file management and sharing and include powerful backup capabilities designed for businesses with a growing data footprint. The unit delivers 2,200 MB/s 64K sequential read and 1154 MB/s sequential write performance1, and can be optionally enhanced with SSD cache and 10/25Gb Ethernet2.

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Compute

Compute

AMD Ryzen V1500B quad-core 2.2 GHz

Throughput

Throughput

2,200 MB/s seq. read and 1154 MB/s seq. write performance1

Memory

Memory

4 GB ECC DDR4, up to 32 GB

Scalability

Scalability

Up to 24 drive bays with RX1217(RP)

High performance storage for anything

Over 106K/59K random read/write IOPS and up to 2,200/1,154 MB/s sequential read/write throughput ensure ample performance for demanding workloads.1

4K Random IOPS Sequential Throughput

* compared to predecessor RS2418(RP)+

Read

0 %
faster*

Write

0 %
faster*

Read

0 %
faster*

Write

0 %
faster*

Built for reliability

Redundant power3

Near-zero downtime

Data integrity and protection

RS2421RPplus_back

Customize to suit

Easily adapt RS2421+/RS2421RP to any business environment by adding faster networking, local SSD cache, or storage capacity.2

  • 10/25GbE ready

  • SSD cache4

  • Storage expansion

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Customize to suit

Easily adapt RS2421+/RS2421RP to any business environment by adding faster networking, local SSD cache, or storage capacity.2

10/25GbE ready

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SSD cache4

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Storage expansion

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Serving remote workforces

Keep your remote workforce connected with powerful out-of-the-box solutions for collaboration, file sharing, and communication.

  • drive

    Synology Drive

  • office

    Synology Office

  • chat

    Synology Chat

Serving remote workforces

Keep your remote workforce connected with powerful out-of-the-box solutions for collaboration, file sharing, and communication.

drive

Synology Drive

office

Synology Office

chat

Synology Chat

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

Central Management System

Conveniently manage your fleet of Synology NAS from a centralized console.

Learn more
Synology Drive

Synology Drive

Instantly access your NAS files across multiple devices whenever you want, wherever you are.

Learn more
Collaboration Suite

Collaboration Suite

Satisfy all team collaboration needs behind the safety of your own private cloud with Synology Office, Calendar, and Chat.

Learn more
Virtual Machine Manager

Virtual Machine Manager

Run various operating systems in isolated sandboxes. Seamlessly clone, store, and migrate virtual machines.

Learn more
Security

Security

Secure data with comprehensive built-in security tools to protect your devices against evolving threats.

Learn more
Surveillance Station

Surveillance Station

Complete surveillance solution for recording, monitoring, and management.

Learn more

Hardware Specifications

CPU

CPU

CPU Model AMD Ryzen V1500B
CPU Quantity 1
CPU Architecture 64-bit
CPU Frequency 4-core 2.2 GHz
Hardware Encryption Engine (AES-NI)

Memory

Memory

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)
Notes
  • Please select Synology memory modules for optimum compatibility and reliability. Synology will not provide complete product warranty or technical support if non-Synology memory modules are used for memory expansion.
  • Synology reserves the right to replace memory modules with the same or higher frequency based on supplier's product life cycle status. Rest assured that the compatibility and stability have been strictly verified with the same benchmark to ensure identical performance.

Storage

Storage

Drive Bays 12
Maximum Drive Bays with Expansion Unit 24 (RX1217/RX1217RP x 1)
Compatible Drive Type* (See all supported drives)
  • 3.5" SATA HDD
  • 2.5" SATA HDD
  • 2.5" SATA SSD
Maximum Single Volume Size* 108 TB
Hot Swappable Drive
Notes
  • It is strongly recommended that you only install drives listed on your device's compatibility list. Storage pool and volume creation processes may fail when using unverified drives. Synology is unable to provide technical support for devices using unsupported components.
  • "Compatible drive type" indicates drives that have been tested to be compatible with Synology products. This term does not indicate the maximum connection speed of each drive bay.
  • Each internal volume (may consist of multiple drives) is expandable up to 108TB.

External Ports

External Ports

RJ-45 1GbE LAN Port 4 (with Link Aggregation / Failover support)
USB 3.2 Gen 1 Port* 2
Expansion Port 1
Notes The USB 3.0 standard was renamed to USB 3.2 Gen 1 by the USB Implementers Forum (USB-IF) in 2019.

PCIe

PCIe

PCIe Expansion 1 x Gen3 x8 slot (x4 link)

File System

File System

Internal Drives
  • Btrfs
  • EXT4
External Drives
  • Btrfs
  • EXT4
  • EXT3
  • FAT
  • NTFS
  • HFS+
  • exFAT

Appearance

Appearance

Form Factor (RU) 2U
Size (Height x Width x Depth) RS2421+ : 88 mm x 482 mm x 552 mm
RS2421RP+ : 88 mm x 482 mm x 578 mm
Weight RS2421+ : 11.5 kg
RS2421RP+ : 11.9 kg
Rack Installation Support* 4-post 19" rack (Synology Rail Kit - RKS1317)
Notes The rail kit is sold separately

Others

Others

System Fan 60 mm x 60 mm x 3 pcs
Fan Speed Mode
  • Full-Speed Mode
  • Cool Mode
  • Quiet Mode
Easy Replacement System Fan
Power Recovery
Noise Level* RS2421+ : 50.1 dB(A)
RS2421RP+ : 54 dB(A)
Scheduled Power On / Off
Wake on LAN / WAN
Power Supply Unit / Adapter RS2421+ : 500 W
RS2421RP+ : 350 W
Redundant Power Supply RS2421+ : -
RS2421RP+ :
AC Input Power Voltage 100 V to 240 V AC
Power Frequency 50/60 Hz, Single Phase
Power Consumption* RS2421+ : 79.56 W (Access)
34.89 W (HDD Hibernation)
RS2421RP+ : 91.76 W (Access)
48.21 W (HDD Hibernation)
British Thermal Unit RS2421+ : 271.65 BTU/hr (Access)
119.13 BTU/hr (HDD Hibernation)
RS2421RP+ : 313.31 BTU/hr (Access)
164.61 BTU/hr (HDD Hibernation)
Notes
  • Power consumption is measured when it is fully loaded with Western Digital 1TB WD10EFRX hard drive(s).
  • Noise Level Testing Environment: Fully loaded with Seagate 2TB ST2000VN000 hard drive(s) in the idle state. Two G.R.A.S. Type 40AE microphones, each set up 1 meter away from the Synology NAS at the front and rear. Background noise: 16.49-17.51 dB(A); Temperature: 24.25-25.75˚C; Humidity: 58.2-61.8%

Temperature

Temperature

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

Certification

Certification

  • FCC
  • CE
  • BSMI
  • EAC
  • CCC
  • KC
  • UL
  • VCCI
  • RCM

Warranty

Warranty

3 Years
Notes The warranty period starts from the purchase date as stated on your purchase receipt. (Learn more)

Environment

Environment

RoHS Compliant

Packaging Content

Packaging Content

RS2421+ :
  • Main Unit X 1
  • Accessory Pack X 1
  • AC Power Cord X 1
  • Quick Installation Guide X 1

RS2421RP+ :
  • Main Unit X 1
  • Accessory Pack X 1
  • AC Power Cord X 2
  • Quick Installation Guide X 1

Optional Accessories

Optional Accessories

Notes All memory modules will operate at the maximum frequency specified by the CPU manufacturer.

DSM Specifications

Storage Management

Storage Management

Maximum Internal Volume Number 64
SSD Read / Write Cache (White Paper)
SSD TRIM
Supported RAID Type
  • Synology Hybrid RAID
  • Basic
  • JBOD
  • RAID 0
  • RAID 1
  • RAID 5
  • RAID 6
  • RAID 10
RAID Migration
  • Basic to RAID 1
  • Basic to RAID 5
  • RAID 1 to RAID 5
  • RAID 5 to RAID 6
Volume Expansion with Larger HDDs
  • Synology Hybrid RAID
  • RAID 1
  • RAID 5
  • RAID 6
  • RAID 10
Volume Expansion by Adding a HDD
  • Synology Hybrid RAID
  • JBOD
  • RAID 5
  • RAID 6
Global Hot Spare Supported RAID Type
  • Synology Hybrid RAID
  • RAID 1
  • RAID 5
  • RAID 6
  • RAID 10

File Services

File Services

File Protocol SMB/AFP/NFS/FTP/WebDAV
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
Notes
  • Regarding data concerning tests with RAM expansion, all memory slots are installed with the maximum capacity of supported RAM.
  • The testing standard was based on the maximum number of concurrent connections supported by this model. During the testing, 25% of the connections were used to transfer files concurrently. The transfer process guaranteed that the connections were not interrupted; the minimum transfer speed was not guaranteed.

Account & Shared Folder

Account & Shared Folder

Maximum Local User Accounts 2,048
Maximum Local Groups 256
Maximum Shared Folder 512
Maximum Shared Folder Sync Tasks 16

High Availability

High Availability

Synology High Availability

Log Center

Log Center

Syslog Events per Second 1,000

Virtualization

Virtualization

VMware vSphere with VAAI
Windows Server 2016
Windows Server 2019
Citrix Ready
OpenStack

General Specifications

General Specifications

Networking Protocols SMB1 (CIFS), SMB2, SMB3, NFSv3, NFSv4, NFSv4.1, NFS Kerberized sessions, iSCSI, HTTP, HTTPs, FTP, SNMP, LDAP, CalDAV
Supported Browsers
  • Google Chrome
  • Firefox
  • Microsoft Edge
  • Safari
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)

Antivirus by McAfee (Trial)

Central Management System

Central Management System

Synology Chat

Synology Chat

Maximum Users 1,500
Notes
  • The number of concurrent HTTP connections for Synology Chat was configured to the maximum.
  • For tested models with expandable memory, the maximum amount of RAM was installed.

Document Viewer

Document Viewer

Download Station

Download Station

Maximum Concurrent Download Tasks 80

SAN Manager

SAN Manager

Maximum iSCSI Target Number 128
Maximum LUN 256
LUN Clone/Snapshot, Windows ODX
Notes iSCSI Manager has been renamed to SAN Manager in DSM 7.0.

Synology MailPlus / MailPlus Server

Synology MailPlus / MailPlus Server

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
Notes
  • Models with more than 4 bays were installed with two SSDs for SSD cache.
  • For tested models with expandable memory, the maximum amount of RAM was installed.
  • The performance of the mail system will slightly decrease in high-availability mode due to data synchronization between the two servers.
  • Functions that were enabled in all of the tests above: anti-spam, anti-virus, DNSBL, greylist, content scan, full-text search (English only).

Media Server

Media Server

DLNA Compliance

Synology Photos

Synology Photos

Facial Recognition
Notes Photo Station and Synology Moments are succeeded by Synology Photos in DSM 7.0. For a features comparison, check this article.

Snapshot Replication

Snapshot Replication

Maximum Snapshots per Shared Folder 1,024
Maximum of System Snapshots 65,536

Surveillance Station

Surveillance Station

Maximum IP cam (Licenses required) 40 (including 2 Free License) (See All Supported IP Cameras)
Total FPS (H.264) 1200 FPS @ 720p (1280x720)
1050 FPS @ 1080p (1920x1080)
600 FPS @ 3M (2048x1536)
440 FPS @ 5M (2591x1944)
320 FPS @ 4K (3840x2160)
Total FPS (H.265) 1200 FPS @ 720p (1280x720)
1200 FPS @ 1080p (1920x1080)
1120 FPS @ 3M (2048x1536)
600 FPS @ 5M (2591x1944)
480 FPS @ 4K (3840x2160)
Notes
  • Surveillance Station throughput is tested with Axis network camera, using continuous recording with live view from Surveillance Station and motion detection by camera. Live view and recording are sharing the same stream from the camera.
  • The maximum channel number also includes devices installed on Virtual DSM.
  • Total FPS may be affected by other services running at the same time (e.g., archive tasks performed by Archive Vault).

Synology Drive

Synology Drive

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 Number of Concurrent Sync Clients 550 (the number of connections that can be maintained when the recommended number of hosted files was reached)
Notes
  • Exceeding the recommended numbers above will not block application operations, but may result in longer response time.
  • Utilizing SSD cache can significantly improve performance.
  • For tested models with expandable memory, the maximum amount of RAM was installed.
  • Btrfs file system and non-encrypted shared folders were used during the aforementioned testing.

Synology Office

Synology Office

Maximum Users 1,800
Notes
  • Multiple files were opened for testing and each file was edited by 30 users simultaneously.
  • For tested models with expandable memory, the maximum amount of RAM was installed.
  • Client performance may affect maximum simultaneous editing users. Client PCs used for testing: Intel Core i3-3220 / 8GB RAM

Video Station

Video Station

Virtual Machine Manager

Virtual Machine Manager

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.

VPN Server

VPN Server

Maximum Connections 30

Notes:

  1. Model specifications are subject to change without prior notice.
  2. 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.
  3. The actual performance may be lower than lab testing figure due to differences in server configuration, deployment, and the number of active operations.
  4. If usage requirements exceed the specifications above, please contact our regional partners for professional advice.