Ubiquiti UNAS-4-B UniFi Storage with (2) 3.5" HDD bays BLK

Ubiquiti UNAS-4-B UniFi NAS Storage

Overview

The Ubiquiti UNAS-4-B is a compact network-attached storage system purpose-built for UniFi ecosystem deployments. This dual 3.5" HDD bay NAS operates via PoE++ (with included adapter), eliminating the need for separate power infrastructure while maintaining flexible desktop or rack-mount deployment options. Manufactured in the Czech Republic, the UNAS-4-B weighs 5.7 lb and connects via 2.5 GbE networking, making it suitable for medium-scale surveillance, backup, and archival workflows within unified Ubiquiti environments.

Key Features

The UNAS-4-B integrates directly with UniFi management interfaces, allowing centralized configuration and monitoring from existing Ubiquiti controller deployments. The included PoE++ adapter simplifies cabling and reduces power distribution complexity—particularly valuable in retrofit installations where traditional PSU placement is constrained. Two 3.5" HDD bays support capacity expansion up to 8TB per bay (16TB total) depending on drive selection. The 2.5 GbE connection provides sufficient throughput for concurrent recording streams and archival operations in small-to-mid-sized installations without introducing bottlenecks.

Deployment Scenarios

The UNAS-4-B excels in branch office and remote site deployments where IT overhead must remain minimal. A typical use case involves pairing with UniFi Protect camera systems for local event storage and redundancy, reducing bandwidth pressure on primary data centers. The compact form factor allows placement in network cabinets, wall-mounted enclosures, or desktop environments without substantial footprint impact. PoE++ power delivery is particularly advantageous in installations where UPS battery backup or managed power distribution is already in place.

Network Integration

As a native UniFi accessory, the UNAS-4-B model operates within the broader Ubiquiti ecosystem, supporting unified authentication, monitoring dashboards, and backup scheduling through the UniFi interface. The 2.5 GbE connection accommodates typical surveillance data rates while remaining compatible with standard PoE++ switches and injectors. Network configuration requires minimal manual intervention when deployed alongside other UniFi hardware.

Installation Notes

The UNAS-4-B ships with the PoE++ power adapter included, reducing procurement complexity. Drive installation follows standard 3.5" bay procedures. Physical mounting options accommodate both vertical and horizontal orientation, though airflow and thermal considerations should inform placement decisions. Confirm PoE++ port availability on your switch before deployment; standard PoE injectors are insufficient for this unit.

Karl Wilson, Infrastructure Engineer

"The UNAS-4-B model fills a legitimate gap for teams standardized on Ubiquiti infrastructure. Power-over-Ethernet operation eliminates a separate failure point, and native UniFi integration means no third-party management console overhead. The dual 3.5" configuration supports modest workloads without demanding complex RAID tuning. However, confirm your 2.5 GbE switching capacity before committing to concurrent multi-stream recording scenarios—throughput can become constraining at scale. For organizations deploying 10+ cameras, evaluate whether a higher-capacity appliance makes financial sense over multiple UNAS-4-B units."