SYNOLOGY Expansion Unit Dx1215ii 12-bay

The Synology DX1215II is a 12-bay HDD/SSD expansion enclosure designed to add additional storage to a Synology DiskStation. Supporting 2.5" and 3.5" drives with Serial ATA interfaces and hot-swap capability, the DX1215II expands capacity up to the supported limits of the host DiskStation while maintaining a compact desktop footprint. The unit is finished in black and weighs approximately 9.02 kg.

Advantages

The DX1215II provides a straightforward way to increase storage density by adding up to 12 drives without requiring extensive reconfiguration of the host DiskStation. It supports online volume and RAID expansion through DiskStation Manager (DSM) to minimize service disruption. Drives developed and validated by Synology are fully interoperable with Synology systems, and the plug-and-play design simplifies installation and unified drive management via DSM.

Suitable for

• Small and medium business environments needing extra NAS capacity
• Home or office users expanding an existing Synology DiskStation
• Use cases requiring hot-swap drive replacement and online RAID expansion

Key specifications

• Model: Synology DX1215II
• Drive bays: 12 (supports 2.5" and 3.5" drives)
• Interface: Serial ATA (SATA I/II/III)
• Maximum supported capacity: depends on host DiskStation (example aggregated capacity up to 192 TB with compatible drives)
• Hot-swap support: Yes
• Colour: Black
• Weight: 9.02 kg

How to use

Connect the DX1215II to a compatible Synology DiskStation following the host device’s expansion slot and connection instructions. Install drives into the enclosure bays, then power on the unit and access DiskStation Manager (DSM) on the host. Use DSM to detect the expansion unit, add new volumes, or expand existing RAID volumes online. Hot-swap drives as needed following safe removal procedures in DSM to avoid data loss.

Recommendations

Install drives that are validated for Synology systems to ensure compatibility and reliability. When expanding RAID volumes, perform backups of critical data before making structural changes and monitor drive health via DSM for proactive maintenance.