Synology Inc.

Refurbished DiskStation DS420+

Streamline your data management

Synology Certified Refurbished

Access Synology solutions in a cost-effective and environmentally responsible way. All certified refurbished products are put through extensive testing, comply with stringent quality standards, and come with a 2-year warranty.

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High performance NAS with SSD cache acceleration capability

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Capable and compact

Powerful functionality packed into a 4-bay chassis

Consolidate and share

Store, organize, and share up to 72 TB of data.

Integrated data protection

Contains hardware and software safeguards engineered to protect your data — trusted by millions.

A capable all-around performer

The versatile DS420+ can serve as a central storage device as well as a multimedia hub.

The DS420+ features two M.2 NVMe slots for caching

Btrfs: advanced file system for data protection

The Synology DiskStation Manager (DSM) operating system that powers DS420+ uses the advanced Btrfs file system, which safeguards your data against corruption and allows for the reversal of any unintended or malicious changes through the use of snapshot technology. Learn more

Store, share, and protect

Manage all your documents, photos, and other files, back up applications and devices, and protect your physical assets with professional video surveillance.

Private cloud for seamless data access

A private cloud for all your devices

Store, sync, access, and share data from any device, wherever you are. Work seamlessly between different platforms and devices, and access your files through mobile apps, desktop clients, and a browser-based interface. Quickly and easily roll back files in case of accidental deletion, mistakes, malware, etc., with the versioning feature. Learn more

Keep your photos organized

Efficiently back up and organize photos and videos with management tools for amateurs and professionals. Automatically organize your content into albums and create secure share links for family, friends, or clients. Learn more

Effortlessly keep multiple Synology NAS in sync

Collaborate with minimal downtime using site-to-site file syncing, which can be configured to automatically synchronize individual files or folders between Synology devices, allowing seamless file access.

Share data with the power of the cloud

Reduce your on-site storage footprint and benefit from data center network speeds with hybrid cloud technology. The optional Hybrid Share service provides efficiently storage of cold data in the cloud, while keeping frequently accessed files cached locally on your DS420+ and accessible at LAN speeds.

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Multi-layered backup

Back up PCs, smartphones, cloud apps, and more

Consolidate and automate backup tasks for PCs, file servers, VMs, SaaS applications, and more with Active Backup Suite. Administer device backups remotely through a centralized portal and quickly restore specific files or entire devices to keep your business up and running. Take advantage of built-in remote backup solutions designed to protect your data with seamless 3-2-1 backup configurations. Learn more

Perform full Synology system backups

Protect all data, applications, and configurations on your Synology systems with comprehensive scheduled backups to local and remote servers, external drives, or cloud storage destinations including Synology C2 Storage. Learn more

Protect folders and LUNs with snapshots

Configure efficient point-in-time snapshots of shared folders and LUNs at intervals as short as 5 minutes. Allow users to easily restore previous versions of files unassisted, quickly recover VMs, and copy snapshots to another server to benefit from rapid storage failover. Learn more

Smart surveillance

Synology Surveillance Station

Protecting your business has never been easier, with centralized management, support for over 8,300 IP camera models, and remote monitoring and playback. Synology’s video management system provides all the tools you need for live monitoring, investigation, management, and backup.

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Dual recording to the cloud

C2 Backup for Surveillance allows you to keep access to surveillance footage if your recording server is disabled by recording to your local server as well as C2 cloud. End-to-end encryption protects streams against unauthorized access while low latency recording lets you review the crucial last few seconds before the recording server was lost.

Performance backed by Synology drives

Leverage high sustained performance and reliability with enterprise-grade drives and built-in data protection designed for Synology systems.

HDD

Enterprise Series 3.5" SATA

Plus Series 3.5" SATA

SSD

Enterprise Series 2.5" SATA

Enterprise Series M.2 NVMe

Get more with DiskStation Manager

Take advantage of a host of native productivity, management, and security solutions available in the web-based Synology DSM operating system.

Desktop Backup

Simplified backup solution for your Mac, PC, and mobile devices.

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DSM UI

Award-winning operating system with an intuitive user interface and powerful capabilities.

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Snapshot Replication

Schedulable and instantaneous data protection for shared folders and iSCSI LUNs for disaster prevention.

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Synology Drive

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

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File Server/Management

Powerful built-in file management and sharing services.

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Security

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

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Hardware Overview

1Status indicator
2Drive status indicator
3Drive tray lock

4USB 3.0 port
5Power button and indicator
6Drive tray

71GbE RJ-45 port
8Reset button
9Power port

10System fan
11Kensington Security Slot

More ways to harness your NAS

Storage for content creators

Synology NAS brings speed, simplicity, and security to all your creative projects.

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Complete endpoint protection

Follow the 3-2-1 backup strategy and keep your data safe with Synology’s backup packages.

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Ransomware prevention and protection

Minimize the threat posed by increasingly sophisticated ransomware and other malware with Synology solutions.

Learn more

Notes:SSD cache can be enabled by installing Synology SNV3400 M.2 NVMe SSD drives into the built-in M.2 slots. Drives are sold separately.C2 Storage for Hyper Backup and Hybrid Share requires purchase of an eligible annual or monthly subscription. A free trial is available for each newly registered Synology Account. Learn more Surveillance Station includes 2 free licenses. Connecting more cameras and devices requires additional licenses.PCIe add-in cards, expansion units, and storage drives are sold separately. Refer to the compatibility list for compatible devices.

Hardware Specifications
CPU
CPU	CPU Model	Intel Celeron J4025
	CPU Quantity	1
	CPU Core	2
	CPU Architecture	64-bit
	CPU Frequency	2.0 (base) / 2.9 (turbo) GHz
	Hardware Encryption Engine
Memory
Memory	System Memory	2 GB DDR4 non-ECC
	Total Memory Slots	1
	Maximum Memory Capacity	6 GB (2 GB + 4 GB)
	Notes	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. 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.
Storage
Storage	Drive Bays	4
	M.2 Drive Slots	2 (NVMe)
	Drive Type (See all supported drives)	3.5" SATA HDD 2.5" SATA HDD 2.5" SATA SSD M.2 2280 NVMe SSD
	Hot Swappable Drive*
	Notes	The hot swappable drive feature is not supported by M.2 SSD slots.
External Ports
External Ports	RJ-45 1GbE LAN Port	2
	USB 3.2 Gen 1 Port	2
Appearance
Appearance	Size (Height x Width x Depth)	166 mm x 199 mm x 223 mm
	Weight	2.18 kg
Others
Others	System Fan	92 mm x 92 mm x 2 pcs
	Fan Speed Mode	Full-Speed Mode Cool Mode Quiet Mode
	Brightness Adjustable Front LED Indicators
	Power Recovery
	Noise Level*	19.8 dB(A)
	Scheduled Power On / Off
	Wake on LAN / WAN
	Power Supply Unit / Adapter	90 watts
	AC Input Power Voltage	100V to 240V AC
	Power Frequency	50/60 Hz, Single Phase
	Power Consumption*	28.30 watts (Access) 8.45 watts (HDD Hibernation)
	British Thermal Unit	96.5 BTU/hr (Access) 28.81 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 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
Certification
Certification	FCC CE BSMI EAC CCC KC BIS VCCI RCM
Warranty
Warranty	2 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	Main Unit X 1 Accessory Pack X 1 AC Power Adapter X 1 AC Power Cord X 1 RJ-45 LAN Cable X 2 Quick Installation Guide X 1
Optional Accessories
Optional Accessories	DDR4 non-ECC SODIMM: D4NESO-2666-4G Enterprise Series 3.5" SATA HDD: HAT5300 Series Plus Series 3.5" SATA HDD: HAT3300 Series Enterprise Series 2.5" SATA SSD: SAT5200 Series Enterprise Series M.2 2280 NVMe SSD: SNV3400 & SNV5400 Series
	Notes	All memory modules will operate at the maximum frequency specified by the CPU manufacturer.

DSM Specifications
Storage Management
Storage Management	Maximum Single Volume Size	108 TB
	Maximum Internal Volume Number	64
	SSD Read/Write Cache (Determining cache size)
	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
	Global Hot Spare Supported RAID Type	Synology Hybrid RAID RAID 1 RAID 5
	Notes	Each internal volume (may consist of multiple drives) is expandable up to 108TB. Actual maximum storage pool and volume sizes depend on drive sizes used, the number of drive bays available, and the RAID configuration. Usable capacity for each volume will be lower than the maximum volume size and is dependent on the filesystem and the amount of system metadata stored.
File System
File System	Internal Drives	Btrfs ext4
	External Drives	Btrfs ext4 ext3 FAT32 NTFS HFS+ exFAT
File Services
File Services	File Protocol	SMB AFP NFS FTP WebDAV Rsync
	Maximum Concurrent SMB/AFP/FTP Connections	500
	Maximum Concurrent SMB/AFP/FTP Connections (with RAM expansion)	1,500
	Windows Access Control List (ACL) Integration
	NFS Kerberos Authentication
	Notes	During testing, the maximum number of SSDs supported by this model is installed in a RAID 5 configuration. 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	8
Hybrid Share
Hybrid Share	Hybrid Share Folder Number	10
Hyper Backup
Hyper Backup	Data & Folder Backup
	Entire System Backup
	Notes	Full-system backup requires DSM 7.2 or later.
High Availability
High Availability	Synology High Availability
Log Center
Log Center
Log Center	Syslog Events per Second	800
Virtualization
Virtualization	VMware ESXi 6.5 and VAAI
	Windows Server 2016
	Windows Server 2019
	Windows Server 2022
	Citrix Ready
	OpenStack
General Specifications
General Specifications	Supported Protocols	SMB1 (CIFS), SMB2, SMB3, NFSv3, NFSv4, NFSv4.1, NFS Kerberized sessions, iSCSI, HTTP, HTTPs, FTP, SNMP, LDAP, CalDAV
	Supported Browsers	Chrome Firefox 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
Central Management System
Central Management System
Synology Chat
Synology Chat
Synology Chat	Suggested Users	50
	Notes	Measured with simulated users, each with an average record of 20,000 messages, emojis, or stickers. The required server response time is below ten seconds. Models with expandable memory are tested with the maximum supported quantity installed.
Download Station
Download Station
Download Station	Maximum Concurrent Download Tasks	80
SAN Manager
SAN Manager
SAN Manager	Maximum iSCSI Target Number	128
	Maximum LUN	256
	LUN Clone/Snapshot, Windows ODX
Synology MailPlus / MailPlus Server
Synology MailPlus / MailPlus Server
Synology MailPlus / MailPlus Server	Free Email Accounts	5 (Additional accounts require purchase of licenses)
	Suggested Maximum Users	50
	Notes	The suggested maximum number of users is based on the following workload: 20% of users with a 20,000 item mailbox randomly performing actions and receiving 240 emails per day, and 80% of users receiving 20 emails per day. Learn more Models with SSD support are tested with a single SSD volume. Models with expandable memory are tested with the maximum supported quantity installed. Learn more about memory requirements. Operating in high-availability mode will incur additional overhead. Features enabled during evaluation: anti-spam, anti-virus, DNSBL, greylist, content scanning, and full-text search (English).
Media Server
Media Server
Media Server	DLNA Compliance
Synology Photos
Synology Photos
Synology Photos	Facial Recognition
	Object Recognition
	Notes	Object recognition requires an upgrade of memory capacity to a minimum of 4 GB.
Snapshot Replication
Snapshot Replication
Snapshot Replication	Maximum Snapshots per Shared Folder	1,024
	Maximum of System Snapshots	65,536
Surveillance Station
Surveillance Station
Surveillance Station	Default Licenses	2 (Additional cameras require purchase of licenses)
	Suggested Maximum IP Cameras and Total FPS (H.264)	1080p: 25 channels, 700 FPS 3M: 25 channels, 350 FPS 5M: 24 channels, 240 FPS 4K: 12 channels, 120 FPS
	Suggested Maximum IP Cameras and Total FPS (H.265)	1080p: 25 channels, 750 FPS 3M: 25 channels, 500 FPS 5M: 25 channels, 250 FPS 4K: 20 channels, 200 FPS
	Notes	Performance figures are obtained from testing conducted with the device fully populated with drives, with their default memory configuration, and under a continuous recording setup. Actual system capabilities may vary based on configuration, drive performance, enabled features, and the presence of additional workloads. Use NVR Selector to quickly find a suitable model based on your requirements. The number of streams that can be viewed simultaneously is twice the suggested maximum number of cameras. For example, if the suggested maximum number of cameras for a model is 10 under H.264, 1080p, the model can support up to 20 streams of the same specification at the same time.
Synology Drive
Synology Drive
Synology Drive	Recommended Number of Concurrent Sync Clients	350
	Maximum Number of Hosted Files	5,000,000 (applies to files indexed or hosted by Synology Drive. For file access through other standard protocols, refer to the File Services section above)
	Notes	Models with expandable memory are tested with the maximum supported quantity installed. Exceeding the recommended numbers above will not block application operations, but may result in longer response time. Btrfs file system and non-encrypted shared folders were used during the aforementioned testing.
Synology Office
Synology Office
Synology Office	Suggested Users	600
	Notes	Models with expandable memory are tested with the maximum supported quantity installed. Client performance may affect maximum simultaneous editing users. Client PCs used for testing: Intel Core i3-3220 / 8GB RAM
Virtual Machine Manager
Virtual Machine Manager
Virtual Machine Manager	Recommended Virtual Machine Instances	2 (Learn more)
	Recommended Virtual DSM Number (Licenses required)	2 (including 1 Free License)
	Notes	The specifications vary depending on system configuration and memory size.
VPN Server
VPN Server
VPN Server	Maximum Connections	40

Notes: 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.