Buffalo TeraStation 5420RN 40TB 4-Bay Windows IoT NAS Server (4 x 10TB)

The Buffalo WS5420RN40S9 is a four-bay rackmount NAS server that arrives with 40TB of raw capacity and a Windows operating system already in place. Because it runs Windows Server IoT 2019, it joins Active Directory, supports Group Policy, and allows remote management just like a traditional Windows server, yet it requires no Client Access Licenses. If your office already works inside a Windows domain, the TeraStation feels familiar from the first login.

All four drives are NAS-grade models that Buffalo has pre-tested and installed in a RAID 5 array, giving you 30TB of usable space plus protection against a single drive failure. You can switch to another RAID level if your workflow demands a different balance of speed and redundancy. A native 10 GbE port and 8 GB of error-correcting memory let the unit handle large file transfers, virtualization stores, and multi-camera video archives without slowing the network.

Cloud integration is built in, so you can replicate critical folders to Microsoft Azure or OneDrive for an extra layer of off-site protection. Many small businesses use the TeraStation as a primary file server during the day and as a backup target for laptops and servers after hours. Others install video management software and turn it into a network video recorder that keeps weeks of security footage on site, free from subscription fees.

Every chassis is made in Japan, meets TAA requirements, and carries a three-year warranty. If a question comes up, you have access to Buffalo’s 24 × 7 North America-based support team. The combination of proven hardware, a familiar operating system, and human help on standby makes this NAS a solid choice for offices that cannot afford downtime.

• 40 TB of raw storage provided by four NAS-grade hard drives, pre-configured in RAID 5 for 30 TB of usable capacity
• Windows Server IoT 2019 operating system integrates seamlessly with Active Directory and other Windows services
• 10 GbE network port and 8 GB ECC memory deliver fast and consistent performance during heavy workloads
• No Client Access Licenses required, reducing the total cost of ownership
• Built-in replication with Microsoft Azure and OneDrive for flexible cloud backup
• Suitable for file sharing, on-site backup, disaster recovery, and network video recording
• Made in Japan and TAA compliant for government and regulated environments
• Three-year warranty with round-the-clock North America-based technical support