External HDD to Synology NAS: Best Transfer Methods
How to Move Data from an External HDD to a Synology NAS
Migrating data from an external hard drive to a NAS is a common task for home users and businesses alike. Whether you’re consolidating backups, archiving files, or setting up a new storage system, choosing the right transfer method can save time and prevent data issues.
This guide explains the best methods to transfer data from an external HDD to a Synology NAS, along with performance considerations and best practices.
Why Transfer External HDD Data to a NAS?
External hard drives are useful, but they have limitations:
Single-device access
No redundancy or RAID protection
Higher risk of accidental disconnection or failure
A NAS provides centralized storage, better data protection, and easier access across devices—making it a logical upgrade from standalone drives.
Method 1: Direct USB Connection (Fastest & Simplest)
Most Synology NAS models include USB ports that allow direct connection of external hard drives.
How it works
Plug the external HDD into the NAS USB port.
Open File Station in DSM
Locate the external drive (usually under “usbshare”)
Copy or move files to your desired shared folder
Pros
Fast transfer speeds
No network dependency
Simple setup
Cons
Requires physical access to the NAS
File systems must be supported (NTFS, exFAT, EXT)
This is the preferred method for large, one-time transfers.
Method 2: USB Copy Tool for Automated Transfers
Synology’s USB Copy package automates file transfers when a drive is connected.
Best for
Repeated imports
Non-technical users
Backup-style workflows
Key benefits
One-touch copy buttons (on supported models)
Scheduled or automatic copying
Clear transfer rules
This method is ideal when external drives are used regularly.
Method 3: Transfer via a Computer (Network-Based)
You can connect the external HDD to a computer and copy files over the network to the NAS.
When to use
USB port compatibility issues
Small or selective file transfers
Remote NAS locations
Limitations
Slower than direct USB
Dependent on network speed
Less efficient for very large datasets
This method works but is not recommended for multi-terabyte migrations.
Method 4: Rsync or Command-Line Copy (Advanced)
Advanced users may prefer command-line tools.
Use cases
Preserving permissions and metadata
Verifying data integrity
Complex directory structures
This approach requires technical knowledge but offers granular control.
Performance Tips for Large Transfers
To optimize transfers:
Use wired Ethernet, not Wi-Fi.
Disable unnecessary services during migration
Avoid transferring during peak usage hours.
Check available storage and RAID health first
Proper preparation prevents slowdowns and interruptions.
Synology-Focused Storage Migration Capabilities
Synology NAS systems are designed to simplify data migration from external storage. DSM supports direct USB access, automated copy tools, detailed progress monitoring, and error reporting. These features allow users to move data safely while maintaining folder structure and file integrity. For large migrations, Synology’s platform ensures stability even during long-running transfer operations.
Common Mistakes to Avoid
Disconnecting drives mid-transfer
Ignoring file system compatibility
Running transfers on degraded storage pools
Copying data without verifying available space
Avoiding these mistakes reduces the risk of data loss or corruption.
How Epis Technology Helps with Data Migration
Epis Technology assists organizations and individuals with secure data migrations to Synology NAS systems. The team evaluates the best transfer method based on data size, file structure, and time constraints. Epis Technology also verifies data integrity after migration, configures storage layouts, and ensures backups are in place before and after the transfer—reducing risk during critical data moves.
Transferring data from an external HDD to a Synology NAS can be quick and reliable when the right method is used. For large datasets, direct USB transfers or automated copy tools offer the best performance, while network-based methods work for smaller jobs.
With Synology’s built-in migration features and expert support from Epis Technology, you can move data confidently and build a more secure, scalable storage environment.
About Epis Technology
Epis Technology provides enterprise IT infrastructure, data protection, and Synology consulting services. The company specializes in NAS deployments, data migration, hybrid cloud integration, Microsoft 365 and Google Workspace backups, fully managed PC backups, and business continuity planning. Epis Technology helps organizations protect, manage, and scale their data environments efficiently.