UniFi UNAS Pro 4 Review: The SMB Case for Ubiquiti's Best 1U NAS

The UNAS Pro 4 is a 1U rackmount NAS with dual 10G SFP+, NVMe caching, four hot-swap bays, and no per-seat licensing — at $499. The hardware value is clear, but its performance in a real business environment is what matters.

This review covers what the UNAS Pro 4 looks like in a managed SMB deployment: Active Directory integration in practice, UniFi Drive 4.0 capabilities and limits, physical constraints that matter at purchase time, and who the product is genuinely suited for.

iFeelTech runs UNAS hardware in production across client sites. This review reflects that experience.

What the UNAS Pro 4 Is (and What It Is Not)

Unlike traditional NAS platforms, the UNAS Pro 4 operates strictly as a file and backup appliance running Ubiquiti's license-free UniFi Drive. It does not run Docker containers, virtual machines, or iSCSI targets. Understanding that boundary upfront clarifies the product's value for the right buyer and its limitations for the wrong one.

The UNAS Pro 4 is part of the next-gen UNAS lineup announced at UniFi World Conference 2025, alongside the UNAS 2, UNAS 4, and UNAS Pro 8. It ships with UniFi Drive 4.0, which added Microsoft 365 OneDrive backup, encrypted volumes, and Identity Endpoint for remote access.

How Does the UNAS Pro 4 Compare to Synology and the Original UNAS Pro?

At $499, the UNAS Pro 4 includes dual 10G SFP+ networking and dual NVMe cache slots natively, with no licensing fees and no add-in cards required.

In the 1U rackmount category, no direct equivalent exists at this price from Synology or QNAP. The Synology RS422+, the closest 1U four-bay competitor, is priced around $700–$800 and requires a proprietary expansion card for 10GbE, with no NVMe cache support. Within Ubiquiti's own lineup, the original UNAS Pro costs the same $499 but uses a larger 2U chassis with seven drive bays and no NVMe caching. The relevant trade-off is simple: the UNAS Pro 4 suits buyers with tight rack space and 10G SFP+ infrastructure already in place; the original 7-bay model suits buyers who need more raw storage capacity and have 2U available.

For UniFi ecosystem buyers with 10G SFP+ switches already in place — USW-Pro, USW-Enterprise, or UCG Fiber — the 10G uplinks on the UNAS Pro 4 are included at $499, with no licensing or additional hardware required.

Deploying the UNAS Pro 4 in an SMB Environment

Here is our deployment experience — from initial setup to Active Directory integration, replication, and cloud backup — across production deployments in managed UniFi environments.

Initial Setup and UniFi Console Integration

After physical installation and network connection, the UNAS Pro 4 appears in the UniFi console through the standard adoption flow — the same process used to adopt a switch or access point. There is no separate setup portal, no secondary login, and no additional management interface to bookmark.

UniFi Drive is accessible directly from the console dashboard. Storage pool creation, RAID configuration, and share management all happen inside the same interface used to manage network topology and camera feeds. Storage alerts and hardware events surface in the Site Manager timeline alongside switch and AP events — no separate monitoring dashboard is required.

Storage pool setup is guided and clear. We have configured both RAID 5 and RAID 6 setups during deployments. RAID 6 is the appropriate choice for most SMB environments; it tolerates two simultaneous drive failures and buys time for replacement without data loss.

Throughput in practice: In production deployments with two M.2 NVMe drives installed and a RAID 6 array, cached sequential reads consistently reach 700–900 MB/s on a 10G link — well into practical 10GbE territory. Without NVMe caching, spinning disk arrays in RAID 5 or 6 typically deliver 200–400 MB/s sequential throughput depending on drive model, sufficient for most SMB file sharing workloads but far short of 10Gbps saturation. Install both M.2 cache slots.

NVMe slots are cache only: The dual M.2 slots are strictly read/write cache — they cannot be provisioned as a primary storage volume. Maximum cache capacity per slot is 4 TiB. This differs from some Synology and QNAP models that allow NVMe drives as standalone storage pools.

SFP+ transceiver note: The UNAS Pro 4 connects via SFP+ only — there is no built-in 10GBASE-T (copper RJ45) port. If your switch infrastructure uses standard 10G RJ45 ports rather than SFP+, you will need SFP+ to RJ45 transceivers at approximately $30–$65 per port. These also generate additional heat and should be factored into rack thermal planning.

RAM is fixed: The 8 GB of RAM is soldered to the board and is not user-upgradable. IT managers cross-shopping with Synology models — where RAM is often expandable — should note this ceiling. For most SMB file server workloads, 8 GB is sufficient, but it is a hardware boundary to plan around.

Noise profile: The UNAS Pro 4 uses small, high-RPM fans typical of a 1U chassis. Under load, it is louder than a desktop NAS or 2U unit with larger fan blades. It is appropriate for a dedicated server room, network closet, or rack enclosure — not for placement near workstations or in open office environments.

Creating SMB Shares and Managing Users

Creating file shares, setting folder-level permissions, and enabling SMB access all happen inside UniFi Drive. The interface is functional and direct — not DSM-level polished, but not confusing either.

Windows clients map drives via standard UNC path once shares are configured (e.g., \\nas-hostname\ShareName). macOS clients connect over SMB cleanly using the Finder Connect to Server dialog. Time Machine is natively supported for Mac endpoint backups, which covers the most common Mac-in-office workflow without additional configuration.

User management is where UniFi's ecosystem integration becomes a genuine differentiator. Through UniFi Identity, user accounts created in the Identity portal are available to UniFi Drive for share access — you are not maintaining a parallel local user list on the NAS. For offices with five-to-twenty-five users, this centralized identity management is exactly the kind of operational simplification that makes the platform worth considering.

Does the UNAS Pro 4 Support Active Directory Integration?

Yes, the UNAS Pro 4 supports basic Active Directory authentication via UniFi Identity, but it does not perform a traditional domain join and does not support deep OU permission inheritance.

UniFi Identity allows AD-synced users to authenticate to SMB shares using their existing domain credentials, eliminating local NAS user management. The Drive 4.0 update added Identity Endpoint, which provides one-click remote SMB drive mapping from mobile or desktop. However, the UNAS Pro 4 does not register as a computer object in Active Directory. Organizations relying on granular OU-level access controls, folder redirection via GPO, or complex permission inheritance trees will find this integration too basic for their environment.

Deployment nuances every MSP should know before rollout:

• Email address requirement: Every AD user account must have an associated email address to sync into UniFi Identity. Accounts without email addresses will not display or authenticate. Audit your AD users before deployment.
• Windows Server 2025 functional level: Domains at the Server 2025 functional level currently face authentication timeouts — users authenticate but are immediately logged out. Server 2019 and Server 2022 functional levels work reliably. Test in a staging environment before production deployment if your domain has been upgraded.

NAS-to-NAS Backup and the Cluster Advantage

The UNAS Pro 4 supports UNAS-to-UNAS replication, where a second unit — at the same location or a remote site — serves as a scheduled backup target.

Setting up replication in UniFi Drive is direct. You create a replication job, specify the source share, point it at the remote UNAS device, and configure the schedule. Jobs run on a timer and report completion status back to the console. On failure, alerts appear in the Site Manager timeline alongside other infrastructure events — not in a separate monitoring dashboard.

iFeelTech runs this configuration at client sites: a primary UNAS at the main office and a second UNAS at a secondary location, with scheduled replication running nightly. The replication is reliable. Failover awareness — knowing when a job has failed versus when bandwidth was temporarily unavailable — requires monitoring the Site Manager feed, but the data is there.

This two-unit replication model, combined with cloud backup, satisfies the 3-2-1 backup rule entirely within UniFi Drive:

• Copy 1: Primary UNAS at the main office
• Copy 2: Replicated UNAS at a secondary site or colocation
• Copy 3 (offsite): Cloud backup to Backblaze B2, AWS S3, or a similar target

All three legs are configurable from the same interface, without third-party agents.

Cloud Backup Integration

Cloud backup targets include Google Drive, OneDrive, Dropbox, AWS S3, Backblaze B2, and Wasabi — all configurable from UniFi Drive without third-party software. For many SMBs, Backblaze B2 is a popular choice due to its S3 compatibility and lower cost per TB.

The Drive 4.0 update also added OneDrive for Business backup, covering OneDrive data from Microsoft Entra ID-managed work accounts. For businesses on Microsoft 365, this provides local, versioned copies of OneDrive content on hardware you physically control. SharePoint and Exchange backup are on Ubiquiti's roadmap but are not available in the current release.

The integration we are most eager to see next is Google Workspace backup. With M365 OneDrive now supported, a matching Google Drive / Workspace backup connector would make the UNAS Pro 4 genuinely compelling for the large share of SMBs running Google-first tech stacks — and would elevate UniFi NAS from a useful storage platform to an essential part of a complete SMB backup posture.

Note: OneDrive for Business backup requires a work or school Microsoft Entra ID account. Personal Microsoft 365 OneDrive accounts (e.g., personal outlook.com subscriptions) are not supported in Drive 4.0.

Drive Compatibility: Can You Use Third-Party HDDs?

Yes. The UNAS Pro 4 accepts standard 3.5" SATA hard drives — WD Red Pro, Seagate IronWolf Pro, and other NAS-rated drives work without issue. Ubiquiti maintains a third-party qualified HDD/SSD list in the UniFi Drive documentation, and using a drive not on that list does not brick the unit or void the warranty. In practice, UniFi Drive may display a compatibility advisory for unrecognized drive models, but the drive will still function. For production deployments, staying within the qualified list avoids that advisory and gives you a clear support path.

Ubiquiti does sell their own UniFi-branded enterprise hard drives — available in 8TB, 16TB, and 24TB capacities — but these are not required. Standard NAS drives from WD, Seagate, and Toshiba install and operate normally. Using a third-party drive may trigger a compatibility advisory in the UI, but there is no functional restriction or lock-in.

What Features Are Missing in UniFi Drive 4.0?

UniFi Drive 4.0 is a file and backup platform. It does not run Docker containers, virtual machines, or iSCSI targets, and that scope is intentional.

For businesses evaluating the UNAS Pro 4 as a file sharing and backup appliance — the intended use case — the absent features above do not affect the purchasing decision. Docker, VMs, and iSCSI are not file server capabilities. If those workloads are required on the same device, Synology or QNAP are the appropriate platforms to evaluate.

What Are the Physical and Technical Constraints of the UNAS Pro 4?

The following constraints are not listed on the spec sheet but are relevant to every deployment decision.

Who Should Buy the UNAS Pro 4?

The UNAS Pro 4 is purpose-built for IT managers and MSPs already running UniFi infrastructure who need a compact, license-free file server with 10G uplinks and a unified management console.

If your storage requirements will outgrow four bays within two years, the UNAS Pro 8 is the more cost-effective choice than buying two UNAS Pro 4 units.

Final Assessment

The UNAS Pro 4 is a well-priced, well-positioned file and backup appliance for businesses already running UniFi infrastructure. At $499, the 1U form factor, dual 10G SFP+ uplinks, and NVMe caching are not matched by competing rackmount products in this price range.

The software gaps — no containers, no VMs, no iSCSI — are real. They are also beside the point for the buyer this product is designed for. The Active Directory integration has clear limits (no traditional domain join, no deep OU inheritance), and two specific deployment nuances — the email address requirement and the Server 2025 functional level issue — need attention before rollout. Neither is a dealbreaker; both are manageable with proper planning.

After deploying UNAS hardware at client sites through both the Drive 3.x and 4.0 generations, the UNAS Pro 4 is the product we recommend to an IT manager with a 1U slot, a UniFi network already in place, and a need for centrally managed file storage and backup.

Frequently Asked Questions

Can the UNAS Pro 4 run Docker or Plex?

No. UniFi Drive 4.0 is a file and backup platform — it does not support Docker containers, virtual machines, or application hosting. Plex Media Server cannot be installed. If you need a NAS that doubles as an application server or media transcoder, Synology or QNAP are the appropriate platforms.

Can I mix drive sizes in the UNAS Pro 4?

No. All drives in the storage array must be identical capacity. There is no equivalent to Synology's SHR (Synology Hybrid RAID) — the array capacity is always bounded by the smallest installed drive. Plan your drive purchases accordingly.

Do I need Ubiquiti-branded hard drives?

No. The UNAS Pro 4 accepts standard 3.5" SATA NAS drives from WD, Seagate, Toshiba, and others. Ubiquiti publishes a third-party qualified drive list; using a drive outside that list may show a compatibility advisory in the UI but will not prevent operation. There is no proprietary drive requirement.

What is UI Care and is it worth it?

UI Care is Ubiquiti's extended warranty program. For the UNAS Pro 4, it costs $129 for 5-year coverage and includes advanced RMA with prepaid return shipping and priority hardware replacement. For MSPs managing client infrastructure, it is worth it — a hardware failure without UI Care means sourcing a replacement unit, whereas UI Care converts that into a next-business-day swap.

Does the UNAS Pro 4 support Personal Microsoft 365 OneDrive backup?

No. The OneDrive for Business backup feature in Drive 4.0 requires a work or school Microsoft Entra ID account. Personal Microsoft 365 subscriptions (personal outlook.com or consumer plans) are not supported. This feature is designed for businesses with a Microsoft 365 Business or Enterprise subscription managed through Entra ID.

Does the UNAS Pro 4 work with a UPS for graceful shutdown?

Not via USB. The UNAS Pro 4 does not have a USB port for connecting a third-party UPS (such as APC or CyberPower). Graceful shutdown on power loss requires the UniFi USP-RPS (rack power station), which communicates over the network. Factor this into your rack planning budget if uninterrupted power protection is required.

For a complete view of the current UniFi NAS lineup, see our UniFi NAS Buyer's Guide 2026.

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Have questions about deploying the UNAS Pro 4 in your environment? Contact iFeelTech — we deploy UniFi storage across South Florida and can advise on the right configuration for your office size and infrastructure.