How to Back Up a Synology NAS to an External USB Drive

Cloud Storage & Data Backup Solutions

A Synology NAS provides centralized storage for business files, backups, media, application data, and other important information. However, storing data on a NAS does not automatically mean the data is fully protected. RAID can help maintain availability when a drive fails, but it does not replace an independent backup.

One straightforward way to create another copy is to back up a Synology NAS to an external USB drive. Synology’s Hyper Backup can copy selected shared folders, application data, and system-related configurations to compatible external storage connected directly to the NAS.

USB backup can provide fast local recovery and an inexpensive additional layer of protection, particularly when combined with offsite or cloud backups.

Why Back Up a Synology NAS to USB?

An external USB drive provides a backup destination that is physically separate from the NAS’s internal storage.

It can help protect against:

Accidental file deletion
Internal drive failures
Storage pool problems
File corruption
Incorrect configuration changes
Certain ransomware incidents
NAS hardware failure

USB drives are also portable. Businesses can rotate multiple drives and store one at another secure location to create additional physical separation.

Choose the Right External USB Drive

Before configuring the backup, estimate how much data needs protection.

The external drive should provide enough capacity for the current backup plus expected growth and, where applicable, multiple backup versions.

Consider:

Current NAS data usage
Expected data growth
Backup retention requirements
USB interface speed
Drive reliability
Replacement lifecycle

Businesses protecting large datasets may need higher-capacity external HDDs rather than smaller portable drives.

Connect the USB Drive

Connect the external drive to a supported USB port on the Synology NAS.

DSM should recognize the attached device and make it available as external storage.

Before using an existing drive, verify that it does not contain information that still needs to be retained. Formatting or repartitioning a drive can destroy existing data.

Administrators should also confirm that the selected filesystem is suitable for the intended environment and workflow.

Install Hyper Backup

Synology Hyper Backup provides centralized backup management for supported NAS environments.

Open Package Center in DSM, locate Hyper Backup, and install it if it is not already available.

After installation:

Open Hyper Backup.
Create a new backup task.
Select the appropriate local folder and USB backup destination.
Choose the connected external storage device.
Select the information that needs protection.

The exact interface can vary depending on the DSM and package versions installed.

Select the Data to Protect

Not every shared folder necessarily needs the same backup schedule or retention policy.

Organizations should identify their most important information first.

Typical backup candidates include:

Business documents
Department shares
Project files
Financial records
User folders
Application information
Configuration data

Avoid blindly copying unnecessary temporary data if it significantly increases backup time and storage consumption.

Configure a Backup Schedule

Manual backups can work for occasional protection, but they depend on someone remembering to run them.

Scheduling improves consistency.

Backup frequency should reflect how often business information changes. A company editing critical files throughout the day may require more frequent protection than an archive that changes only occasionally.

Organizations should consider their Recovery Point Objective, or RPO.

If losing one day of work would be unacceptable, a once-per-day backup may not provide sufficient protection.

Consider Versioned Backups

Keeping only one backup copy can create problems when file corruption or accidental modification is not discovered immediately.

Versioned backups can preserve previous recovery points.

For example, an employee might overwrite an important document and discover the problem several days later. If the USB backup has already replaced the good file with the modified version, recovery may become difficult.

Retention policies should balance recovery requirements against available storage capacity.

Enable Backup Encryption When Appropriate

Portable drives create a physical security consideration.

If someone steals or loses an unencrypted USB drive, information stored on it may potentially be exposed.

Businesses handling confidential information should evaluate backup encryption.

Encryption can help protect:

Customer information
Financial documents
Employee records
Intellectual property
Confidential business files

Encryption credentials or keys must be stored securely. Losing required recovery credentials could make encrypted backup information inaccessible when it is needed.

Run the First Backup

The initial backup may take considerably longer than subsequent jobs because all selected information must be copied.

Backup duration depends on factors including:

Total data volume
USB performance
NAS workload
Number of files
Storage performance

Large multi-terabyte repositories may require many hours to complete.

Whenever practical, schedule the initial backup when storage activity is relatively low.

Verify the Backup

A completed backup notification should not be the end of the process.

Administrators should verify that important files can actually be restored.

Periodically test:

Individual file recovery
Folder restoration
Older backup versions
Backup integrity
Encryption credentials

Recovery testing helps identify problems before an actual hardware failure or data-loss incident occurs.

Safely Disconnect the USB Drive

Do not simply unplug a backup drive while data may still be written to it.

Use DSM’s appropriate eject or disconnect procedure before physically removing the device.

Safe removal reduces the possibility of filesystem corruption or incomplete writes.

For rotating backups, clearly label each drive and document when it was last used.

Consider USB Drive Rotation

Leaving a USB backup permanently connected is convenient, but it reduces physical separation from the production NAS.

Businesses can use multiple drives in rotation.

For example, one drive can remain connected for the current backup while another is securely stored elsewhere.

Rotation can provide additional protection against incidents affecting both the NAS and directly attached storage.

USB Backup Should Not Be Your Only Backup

External drives are useful, but they can fail, become corrupted, be lost, or be damaged in the same physical event as the NAS.

A stronger strategy follows the 3-2-1 backup principle:

Maintain three copies of important data
Use two different storage types
Keep at least one copy offsite

A business might combine Synology production storage, an external USB backup, and an offsite NAS or cloud repository. Strengthen NAS protection with layered business backup solutions.

About Epis Technology

Epis Technology helps organizations design, configure, and maintain reliable Synology backup environments for businesses of all sizes. Services include Hyper Backup configuration, external storage planning, Synology consultation, offsite replication, cloud backup, disaster recovery, cybersecurity, and recovery testing. For organizations that need protection beyond a single USB copy, Epis Technology can design layered backup architectures that combine local recovery with secure offsite protection and long-term business continuity.