TeraStation™ WS5020 - Rackmount 

High Performance Storage Solution for Windows-based Environments- Hard Drives Included


TeraStation WS5020 is an affordable and reliable Network Attached Storage solution integrated with Windows Storage Server 2016 (pre-tested NAS-grade hard drives included). This specialized operating system helps with simple deployment and management of your growing storage demands to integrate seamlessly with your existing Windows-based environment.


WS5020 is an ideal solution for consolidating multiple file servers into a single solution that enables cost reduction and lowering the overhead on your existing servers for other workloads.


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  • Pre-tested NAS-grade hard drives included with RAID pre-configured

  • 3-year warranty with 24/7 North America-based support (Optional Extended Warranty)

  • 4-bay Rackmount NAS with Windows Storage Server 2016 (Standard) with native integration with the Active Directory Service

  • Integrates with Azure, OneDrive, and all other Microsoft based cloud services to create a hybrid cloud

  • No CAL (Client-Access Licenses) required. Cost-effective storage solution to make full use of existing Windows-based environments 

  • Efficient and high speed backup with deduplication feature/native 10GbE port/8GB ECC memory

  • Supports a variety of backup features [Shadow Copy/Azure Backup/iSCSI]

  • Highly secured with the latest SMB protocol support (3.1.1)

  • Business-level sever/PC backup NovaBACKUP® software bundled

  • Made in Japan / TAA compliant / $100 value Rackmount Rail Kit included

Easy and Simple: Smooth integration with your Windows environment

With hard drives included, the TeraStation is a one-stop, all-inclusive backup and recovery storage solution, allowing you to store in your network just by plug and play


Windows Storage Server 2016 provides you seamless integration for expanding storage capability


The device is preconfigured for out-of-the-box use, and WS5020 integrates with your existing Windows environment infrastructures. You can make full use of commonly-used network environments and standard management software you already have for your environment. (More information about Windows Storage Server 2016)


We make it easy for you, and this is the reason why Buffalo NAS is the best choice


  • Pre-tested NAS-grade hard drives included with RAID pre-configured
  • 24/7 North America-based support, including 3 years premium phone support
  • LCD display allows easy visibility of the current unit status
  • TeraStation data can be easily backed up to external storage (DriveStation) or other Rsync-based NAS devices

10GbE Compatible: Ready for future data growth

While having a growth in data and file sizes, you can now benefit greatly from lower-costing 10GbE products. 10GbE-compatible devices and category 6A (Cat 6a) or higher-rated cables allow improvements to office productivity by eliminating network bottlenecks and shortening data backup times.


No 6A cabling in your office? No problem! WS5020 is compatible with IEEE802.3bz and it gives you faster data transfer speeds even with your CAT 5e environment.


With Buffalo's BS-MP20 business switch, users can easily develop faster data transfer environments. (More about 10GbE)

* 4 GB file copy speed: Performance measured with RAID 5 mode
Test Environment (August 2018)
WS5420RN08S6 (RAID 5 configuration) / WS5400RN08S6 (RAID 5 configuration)
[Client PCs]
CPU: Intel (R) Core (TM) i7 7700, M/B: Intel® H270 chipset (ASUS STRIX H270 F GAMING)
Memory: PC - 2700 DDR4 8 GB x 4 (System 16 GB, RAMDISK 16 GB)
NIC: Intel Gigabit CT Desktop Adapter OS: Windows 10 Enterprise 64bit
Install Anti-Virus software ("TrendMicro Virus Buster XG“, Trend Micro Co., Ltd.) to NAS.
While running Virus check on the NAS, copy 4 GB of data from the NAS to 10 PCs on the LAN.
Measure the time until all 10 PCs complete the data download.

Reliable Quality: Designed for 24/7 operation

Your data is secure with our small business purpose build TeraStation, designed for 24/7 operation.


- Peace of mind included with Industry # 1 support


Buffalo Terastation WS5020 is built in Japan and passes severe burn-in testing with NAS-grade hard drives included, thus ensuring compatibility and reliability.

The device comes with free 3-year warranty and 24/7 North America-based support. If problems arise, just one call to our premium phone support desk and we will work tirelessly to resolve your issue.


Buffalo also offers optional Next Business Day / Keep Your Drive warranty options. Warranties can be extended up to 5 years
(Warranty Service).


 - Purpose build & optimized for data storage


The WS5020 series run the Windows Storage Server OS, which is optimized for the data backup and file sharing. Optimal performance with 60 simultaneous client PCs and access for 24 hours.


The NAS hardware is built with business-class components to provide stable 24/7 operation, including server-class 8GB ECC memory to stabilize the performance.

Buffalo's Data Recovery Service

This product qualifies for Buffalo's data recovery service for simple logical data issues.

To receive this service, the device must be registered within its original warranty terms.

hand with latex gloves and a stethoscope checking on a technology hard drive

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Thank You for Your Support

Reliable & easy to use products with personal pre and post-sales support. These are the fundamentals which have helped us win CRN’s ARC award for the 4th year in a row.

Buffalo's Remote Management Service

Save time and resources by accessing these devices from a single console with Buffalo’s free Remote Management Service.





Part Numbers                   



Internal Hard Drives

Number of Drive Bays 4
Number of Included Drives                    4
Capacity Range 16, 32 TB
Drive Interface SATA 6 Gbps
Supported RAID   0/1/5/JBOD (Individual Disks) (Default 5)

USB Interface

Standards Compliance USB 3.0
Connector Type A type
Number of Ports 3x USB 3.0
Data Transfer Rates 5 Gbps


CPU                 Intel Atom C3338
Memory 8GB DDR4 with ECC

Environmental & Power

Power Consumption                   

Max 100W 

Data Transfer 61.7W

Idling 58.7W

Standby 4.9W

Power Supply Internal AC 100-240V Universal 50/60Hz
Operating Temperature 32˚ - 104˚F (0˚ - 40˚C)
Operating Humidity 10 - 85% non-condensing


Product Dimensions
(L x W x H)                 
16.9 x 16.9 x 1.7 in
Product Weight 19.2 lbs
Package Dimensions (L x W x H) 23.0 x 21.3 x 7.9 in
Package Weight 28.7 lbs

LAN Interface

Standards Compliance  IEEE802.3an (10GBASE-T), IEEE802.3bz (5GBASE-T/2.5GBASE-T), IEEE802.3ab (1000BASE-T), IEEE802.3u (100BASE-TX), IEEE802.3 (10BASE-T)
Number of Ports 1 (10GBASE-T), 2 (1000BASE-T)
Data Transfer Rates 10 Gbps / 1000 Mbps / 100 Mbps / 10 Mbps
Supported Protocols TCP/IP
Network File Services CIFS/SMB, AFP, FTP, SFTP, NFS, SNMP
Connector Type RJ-45


Client OS Support 

Windows® 10
Windows® 8.1 (32-bit/64-bit)
Windows® 7 (32-bit/64-bit)
Windows Server® 2016
Windows Server® 2012R2
Windows Server® 2012
Windows Server® 2008R2
Windows Server® 2008
Mac® OS® X 10.11 or later

Compatible Hard Drives

OP-HD2.0N, OP-HD4.0N, OP-HD6.0N, OP-HD8.0N

Optional Warranties KYD (3YKYD30/5YKYD30)
Included Software NAS Navigator2, NovaBACKUP® Buffalo Edition (one server and ten workstation licenses)
Box Contents

TeraStation WS5420RN
AC Cable 
6a Ethernet Cable 
Front Panel Key 
Warranty Statement 
Quick Setup Guide
Setup Media (SD CARD)
Rail Kit with Mounting Brackets and Screws


Value of Hard Drives Included Why Buffalo NAS
Network Attached Storage for Business Chart TeraStation Comparison Chart
TeraStation to Amazon S3 Cloud Integration
TS_to_3rd Party Cloud Support
Perfect case to use TS5010 series TS5010_Solution_Scenario.pdf
Compatible Non Buffalo Drives for TS51210 compatible_non_buffalo_drives.pdf
Perfect Solution Scenario for TS51210 TS51210_Solution_Scenario.pdf
Compatible UPS UPS compatibility list for TeraStation WSS series
Check RAID Configurations



    File Size Post Date Version OS Support Notes
2021-27-01 3.66 Firmware update for WS5020 series units
4.05 MB 2016-25-04 17798 Alpha DD-WRT Pre-release Alpha firmware


    File Size Post Date Version OS Support Notes
2018-04-06 Manuals and Quick Setup Guide for WS5420RN6
2021-27-01 3.66 Readme for FW update for WS5020 series units
2020-27-07 3.0.4 Windows Readme for NAS Navigator for Windows
2019-18-07 2.99 Windows Lisez-moi pour NAS Navigator pour Windows (français)
2019-18-07 2.99 Mac Readme for NAS Navigator for Mac NOTE: For users running MacOS 10.13 or later, download and install the latest version of NAS Navigator2 from Mac App Store.
2019-18-07 2.99 Mac Lisez-moi pour NAS Navigator pour Mac (français) REMARQUE: pour les utilisateurs d'ordinateurs sous MacOS 10.13 ou ultérieur, téléchargez et installez la dernière version de NAS Navigator2 à partir du Mac App Store.
2019-06-03 UPS compatibility list for TeraStation x10 and WSS series


    File Size Post Date Version OS Support Notes
2020-27-07 3.0.4 Windows NAS Navigator for Windows
2019-18-07 2.99 Mac NAS Navigator for Mac NOTE: For users running MacOS 10.13 or later, download and install the latest version of NAS Navigator2 from Mac App Store.
2017-04-01 Link to registration page for all Buffalo products including switches and extended warranties. Also includes setting to provide license information for Novastor NovaBackup software if eligible.


  • WS5020 16 TB - 4 drives included

    • - Rackmount
    • - 4
    • - NAS
    • - 16
  • WS5020 32 TB - 4 drives included

    • - Rackmount
    • - 4
    • - NAS
    • - 32

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