Buffalo WS5420RN40S9

Overview

The Buffalo WS5420RN40S9 is a four-bay rackmount NAS server designed to provide reliable and high-capacity storage for small to medium-sized businesses. Equipped with 40TB of raw storage across four NAS-grade hard drives configured in RAID 5, it offers 30TB of usable space with protection against a single drive failure. Running Windows Server IoT 2019, this NAS integrates seamlessly into Windows environments, supporting Active Directory and Group Policy without requiring Client Access Licenses, making it a familiar and cost-effective solution for offices that depend on Windows networks.

Key features

• Pre-configured RAID 5 array delivers a balance of data protection and storage efficiency with 30TB of usable capacity.
• Windows Server IoT 2019 operating system enables easy integration with existing Windows domains and remote management capabilities.
• Native 10 GbE network port and 8 GB of ECC memory ensure fast and stable performance during large file transfers and heavy workloads.
• Built-in cloud replication supports Microsoft Azure and OneDrive, providing flexible off-site backup options for critical data.
• Versatile use cases including file sharing, on-site backup, disaster recovery, and network video recording without subscription fees.
• Made in Japan with TAA compliance, meeting government and regulated environment standards.
• Three-year warranty backed by 24/7 North America-based technical support for peace of mind and minimal downtime.

Key specs

• Storage capacity: 40 TB raw (4 x 10TB NAS-grade drives)
• Usable capacity: 30 TB in RAID 5 configuration
• Operating system: Windows Server IoT 2019
• Memory: 8 GB ECC RAM
• Network interface: 10 GbE port
• Drive bays: 4 hot-swappable bays
• Warranty: 3 years

Connectivity and compatibility

This NAS server is designed to fit smoothly into Windows-based networks, supporting Active Directory and Group Policy for centralized user and device management. The 10 GbE port allows for high-speed network connections, ideal for environments with large file transfers or virtualization needs. Its compatibility with Microsoft Azure and OneDrive enables straightforward cloud backup integration, enhancing data protection strategies without additional licensing costs.

Performance and reliability

With error-correcting code (ECC) memory and NAS-grade hard drives pre-tested by Buffalo, this unit maintains data integrity and consistent performance even under demanding workloads. The RAID 5 setup protects against single drive failures, reducing the risk of data loss. Its robust hardware and software combination supports multi-camera video archives and virtualization storage, making it a dependable choice for businesses that require continuous access to critical data.

Ideal uses and environments

The TeraStation WS5420RN40S9 is well suited for offices that need a centralized file server with strong data protection and easy integration into existing Windows domains. It works effectively as a primary file server during business hours and as a backup target after hours. Additionally, it supports network video recording for security systems, providing local storage for weeks of footage without recurring fees. Its TAA compliance and build quality also make it a good fit for government and regulated environments.

Orders are processed within 2 business days, which includes verification, packing, and dispatch. Shipping costs are calculated at checkout based on destination, total weight, and selected speed. Free shipping applies to carts over $100 (excluding heavyweight items). All available options and final pricing are clearly shown before payment so you can choose the service that best fits your needs.

Deliveries are handled by major carriers such as USPS, UPS, and FedEx. Estimated delivery times are displayed at checkout and may vary depending on service level and location. Please note that these are estimates and can be affected by weather, holidays, or carrier volume. Once your order ships, you’ll receive a tracking number for real-time updates from pickup to final delivery.

Providing an accurate shipping address helps prevent delays, and changes may be limited once the order has been dispatched. P.O. boxes are supported only when permitted by the selected carrier. Packaging and handoff are optimized to protect items during transit, though oversized or high-weight products may require special handling. All shipping methods and any related constraints are clearly shown during checkout.

Learn more

Returns are accepted within 30 days of delivery. Items must be unused, in the same condition received, and include all tags, manuals, accessories, and original, unaltered packaging. To start a return, please email us for approval. Items sent back without approval may be refused or returned to the sender. If any item is kept, its value will be deducted from the refund.

Non-returnable items include opened TVs, combos, or monitors 37″ or larger, opened computers or software, electronic downloads, opened consumables (film, paper, bulbs, media, ink), custom or modified computers, special-order or “nonreturnable” items, submerged underwater gear, and opened educational media.

After inspection, refunds are issued to the original payment method. Please allow 5–7 business days for the credit to post. Shipping and handling are nonrefundable. If an item is used, incomplete, or not in its original condition, a 30% restocking fee may apply. Direct exchanges are not offered. To exchange an item, please purchase the replacement separately and return the original for a refund.

Learn more

We act solely as a reseller. Any product warranty is provided and administered by the manufacturer, not by our store. That means eligibility, coverage, and outcomes are determined by the manufacturer’s policy for each brand and model. Before purchasing, we recommend reviewing the warranty terms on the manufacturer’s website or in the product documentation to confirm what is covered and for how long.

If you need warranty service, please file the claim directly with the manufacturer. They may require proof of purchase, the product serial number, original packaging, photos, or basic troubleshooting. Some brands ask you to register the product or obtain a case number before shipping it for repair or replacement. We don’t submit or approve claims, but we can point you to the correct support links and contact details.

Keep your invoice and packaging in a safe place, and report any functional issues to the manufacturer as soon as they appear. If you’re unsure whether a problem is covered, the manufacturer’s support team can confirm next steps and timelines. While we cannot intervene in decisions or outcomes, we’re happy to provide purchase documentation or guidance so you can move through the warranty process smoothly.

Learn more