10 Best NAS Expansion Units For Businesses in 2026

Choosing the right expansion-ready NAS can make it easier to grow storage without rebuilding your entire file infrastructure. For businesses, the best options balance capacity, speed, reliability, and room to scale.

This roundup highlights 10 strong picks for teams that need faster shared storage, cleaner backup workflows, and a practical path to future expansion.

Best 10 NAS Expansion Units for Businesses Picks for 2026

Synology Expansion for DiskStation – 5-Bay DX525

The Synology DX525 is a straightforward choice for businesses using a compatible DiskStation and looking for a simple way to add more NAS expansion units for businesses. It adds five 3.5-inch or 2.5-inch SATA HDD/SSD bays, works with Synology DSM tools, and supports hot-swapping for easier drive handling.

Best For: Businesses already on the Synology platform that want quick, plug-and-play expansion.

Pros:

• Adds 5 additional SATA drive bays for supported Synology systems
• Supports hot-swapping and plug-and-play setup
• Managed through Synology DSM unified storage tools
• Backed by a 3-year limited hardware warranty

Cons:

• Only supports drives on Synology’s official compatibility list
• Designed for selected DiskStation units, not universal use

For Synology environments, the DX525 keeps expansion simple and consistent with the rest of the ecosystem. It is best suited to teams that value compatibility, easy administration, and quick capacity growth over broader platform flexibility.

TerraMaster Business NAS – F6-424 6-Bay NAS

The TerraMaster F6-424 is a full NAS platform for businesses that need fast shared storage rather than a pure add-on enclosure. It pairs a quad-core N95 CPU, 8GB of DDR5 memory, dual 2.5GbE ports, and M.2 NVMe support with backup and sync tools aimed at small and medium-sized teams.

Best For: Small and medium-sized businesses that want a high-performance NAS with built-in backup features.

Pros:

• Quad-core N95 CPU with 8GB DDR5 memory for strong business workloads
• Dual 2.5GbE ports with support for link aggregation
• Dual M.2 NVMe slots for SSD caching
• Includes TerraMaster Business Backup Suite for sync, backup, and ransomware protection

Cons:

• Diskless model, so drives must be purchased separately
• Plastic enclosure may matter to buyers looking for a more rugged chassis

If your priority is speed, backup flexibility, and a more feature-rich business NAS, the F6-424 stands out. It is less of an expansion companion and more of an all-in-one storage server for modern teams.

Synology Rack Expansion – 12-Bay DX1222

The Synology DX1222 is a rack-mount expansion unit for selected Synology DiskStation systems that need a major capacity boost. It is designed to configure new storage in minutes with Synology DSM’s unified tools, making it a practical fit for business environments that already standardize on Synology.

Best For: Organizations with compatible Synology systems that need high-capacity rack expansion.

Pros:

• Adds 12 bays for a large storage expansion step
• Rack-mount design suits server-room deployments
• Managed through Synology DSM unified tools
• Backed by a 5-year warranty

Cons:

• Works only with selected Synology diskstation units
• Diskless, so storage drives must be added separately

For teams already invested in Synology, the DX1222 offers a straightforward way to scale storage without changing management workflows. Its main strengths are capacity, rack integration, and long warranty coverage.

Asustor Enterprise NAS – Lockerstor 6 Gen3

The Asustor Lockerstor 6 Gen3 is a high-end NAS for businesses that need strong networking, SSD acceleration, and stability for demanding workloads. It combines an AMD Ryzen Embedded quad-core processor, 16GB ECC DDR5 memory, dual 10GbE plus dual 5GbE ports, and four M.2 NVMe slots for fast storage performance.

Best For: Creators, virtualization users, and businesses that need high-speed, always-on storage.

Pros:

• Dual 10GbE and dual 5GbE ports for high-bandwidth networking
• Four PCIe 4.0 M.2 NVMe slots for caching or all-flash acceleration
• 16GB ECC DDR5 memory for stronger reliability and data integrity
• USB4 40Gbps ports for fast backup and external expansion

Cons:

• Diskless model requires separate drive purchases
• Higher-end feature set may be more than basic file-sharing teams need

This model is built for performance-focused deployments rather than simple storage add-on duty. If your workflow involves heavy multitasking, collaboration, or high-speed transfers, the Lockerstor 6 Gen3 has the hardware to keep up.

Synology Business Expansion Pick – DS925+ 4-Bay Diskless NAS

For businesses that need a compact NAS expansion unit with dependable performance, the Synology DS925+ is built around a 4-bay diskless chassis and Synology’s ecosystem of file, photo, virtualization, and surveillance tools. It is a practical fit when you want stable transfers, dual-network redundancy, and compatibility with drives on the official list.

Best For: Small teams that want a reliable Synology-based storage platform for business files, backups, and shared services.

Pros:

• Up to 522/565 MB/s sequential read/write throughput for stable data transfers.
• Dual 2.5GbE ports add faster network transfer speeds and redundancy.
• Built-in file, photo, virtualization, and surveillance solutions.
• Backed by a 3-year limited hardware warranty.

Cons:

• Diskless model, so drives must be purchased separately.
• Designed to work with drives on Synology’s official compatibility list.

Overall, the DS925+ is a solid choice when your priority is dependable expansion within the Synology platform rather than maximum raw throughput. It makes more sense for businesses that value stability, redundancy, and integrated management tools than for those chasing the lowest upfront cost.

UGREEN Entry Storage Pick – DH2300 2-Bay Desktop NAS

The UGREEN DH2300 is aimed at buyers who want a simple, private starting point for NAS expansion units for businesses or personal use without the complexity of advanced server features. It focuses on easy file backup, photo organization, remote access, and beginner-friendly storage, while staying clear about its more limited performance profile.

Best For: Beginners, solo users, and small offices that need straightforward private storage and backup.

Pros:

• Supports up to 64TB of total capacity in a 2-bay desktop design.
• Includes AI photo album features for tagging faces, locations, text, and objects.
• Automatic backups across Windows, iOS, Android, and macOS devices.
• 1GbE networking and up to 125MB/s file transfers for everyday use.

Cons:

• Does not support Docker or virtual machines.
• Wireless networking requires an external USB adapter.
• Performance is positioned as limited compared with higher-end NAS options.

In practice, the DH2300 is best viewed as an accessible entry point for private storage rather than a heavy-duty business workstation. If your team mainly needs simple backups, media storage, and easy organization, it offers a straightforward path away from cloud subscriptions.

Synology Production Expansion Pick – DS1525+ 5-Bay Diskless NAS

For teams evaluating NAS expansion units for businesses in creative workflows, the Synology DS1525+ is built around shared editing, large media libraries, and network-upgrade flexibility. Its 5-bay diskless design, 10GbE readiness, and support for expansion to 300TB make it a strong fit for production environments that need room to grow.

Best For: Video teams, studios, and multi-user workflows that need fast shared storage and scalable capacity.

Pros:

• Blistering 1,181 MB/s speeds support 4K and 8K editing over the network.
• Can scale from 100TB to 300TB with DX525 expansion units.
• 10GbE ready for shared high-resolution production workflows.
• Includes AI tagging, project version control, and 3-year warranty support.

Cons:

• Diskless model, so storage drives are not included.
• Expansion relies on DX525 units to reach the stated maximum capacity.

The DS1525+ is the most workload-focused option here, especially if you need multiple editors working at once and expect your library to grow quickly. It is a strong match for businesses that prioritize performance, scalability, and shared media management over entry-level simplicity.

Expandable Private Cloud NAS – Synology DS725+ for Small Business Growth

If you need NAS expansion units for businesses that can start modestly and scale over time, the Synology DS725+ is built for that job. This 2-bay diskless NAS can begin with a small drive set and expand to up to 140TB with one DX525 expansion unit, making it a practical fit for growing storage, backup, and surveillance needs.

Best For: Small businesses that want an expandable private cloud with backup and camera support.

Pros:

• Scales from 2 drives to 140TB total with one DX525 expansion unit
• Supports RAID redundancy, automated backups, and snapshot protection
• Can manage up to 30 IP cameras with motion detection and secure remote access
• Backed by a 3-year warranty for ongoing use

Cons:

• Diskless design means drives must be purchased separately
• Only two bays are included before expansion
• Expansion requires the separate DX525 unit

The DS725+ makes sense when you want a compact starting point but expect storage demands to grow. It balances expansion flexibility with protection features and surveillance tools, so it can serve as a central business storage hub rather than a short-term stopgap.

Enterprise Media Storage – Synology DS1825+ for Production Teams

For businesses comparing NAS expansion units for businesses that handle large creative workloads, the Synology DS1825+ is aimed at high-capacity production environments. It scales from 160TB to 360TB with expansion units and is designed for teams that need fast shared storage, strong protection, and network upgrades for demanding workflows.

Best For: Video production teams and other businesses that need fast, expandable shared storage.

Pros:

• Supports growth from 160TB to 360TB with expansion units
• Offers 2,239 MB/s speeds for multi-user file access
• Can support 50+ concurrent users working with 4K/8K projects
• Allows 10GbE or 25GbE network upgrade cards

Cons:

• Diskless design requires separate drive purchases
• Expansion units are needed to reach maximum capacity
• More than a basic office NAS, so it may be overkill for simple file sharing

The DS1825+ stands out when storage performance and expansion headroom matter as much as capacity. It is a strong fit for post-production, archive growth, and teams that need business-grade reliability without giving up speed.

Compact Team NAS – Synology DS425+ for Office File Sharing

If your business wants a straightforward NAS expansion units for businesses option without jumping into a large chassis, the Synology DS425+ is a compact 4-bay choice. It is positioned as a private cloud media server with 278 MB/s speeds, centralized document storage, and protection features that suit day-to-day office sharing.

Best For: Small offices that need a compact shared storage hub for files and media.

Pros:

• 4-bay design gives a simple starting point for office storage
• Provides 278 MB/s speeds for shared files and media
• Includes granular access controls and audit logs for centralized files
• Supports RAID redundancy, automated backups, and snapshots

Cons:

• Storage volume is listed at 80 TB, which is less than larger expandable models
• Diskless configuration means drives are not included
• Not as expansion-focused as higher-capacity enterprise units

The DS425+ is a practical middle-ground model for offices that want secure file sharing and media access in a manageable footprint. It is less about aggressive expansion and more about giving a team dependable centralized storage with familiar Synology protection tools.

How We Picked These NAS Expansion Units for Businesses

We focused on expansion flexibility, business-grade reliability, network speed, and ease of deployment. Priority went to systems and expansion units that can support shared work, backups, virtualization, or media workflows without creating an immediate bottleneck.

We also considered drive bay count, upgrade paths, ECC memory support, multi-gig or 10GbE networking, and whether the platform is better suited to small teams or larger storage environments.

Quick Comparison

For simple capacity growth, dedicated expansion chassis are the easiest route. For new deployments that need both storage and performance, a full NAS with faster networking and more bays is usually the smarter long-term choice. Smaller teams may prefer compact 2-bay or 4-bay systems, while growing businesses should look harder at 5-bay, 6-bay, 8-bay, or 12-bay options.

Key Buying Factors for NAS Expansion Units for Businesses

Expansion Compatibility

Check that the expansion unit works with your existing NAS ecosystem and supports the storage pool or RAID setup you need. Compatibility matters just as much as raw capacity.

Drive Bays and Maximum Capacity

More bays usually mean more flexibility for RAID protection and future growth. Think about both current needs and where your business may be in two to three years.

Network Performance

For file sharing, backups, and collaborative editing, 2.5GbE, 5GbE, or 10GbE can make a major difference. Faster networking helps avoid storage becoming the weak link.

Reliability Features

ECC memory, redundant backup strategies, and dependable hardware are important for businesses that cannot afford downtime or silent data corruption.

Management and Usability

A good business NAS should be easy to monitor, simple to expand, and straightforward to secure. If your team is small, the best platform is often the one your staff can actually maintain well.

Who Should Buy Which NAS Expansion Units for Businesses?

Smaller businesses and teams with light file-sharing needs can start with compact 2-bay or 4-bay systems. Companies expecting growth, more users, or larger backup sets should look at 5-bay and 6-bay models. Larger organizations, media teams, and storage-heavy operations are usually better served by 8-bay or 12-bay options, especially when paired with faster networking.

If your main goal is simple capacity growth, a dedicated expansion chassis is often the most efficient choice. If you need a new primary file server, prioritize performance, upgrade headroom, and software features alongside raw storage. That approach will help you choose NAS Expansion Units for Businesses that stay useful longer as your data demands increase.