USB Copy from Synology NAS to External Drive

Updated 7 November 2026 · Standard formula, shown below

Yes, you can copy files from a Synology NAS to an external drive using the built-in USB Copy feature. You plug a USB drive into the NAS, choose a copy mode in the USB Copy app, and the NAS copies files to or from the drive automatically. This article explains how it works, how to set it up, and what to do when it doesn’t behave as expected.

What USB Copy Does

USB Copy is a package included with Synology DiskStation Manager (DSM). It manages file transfers between the NAS and any USB storage device connected to one of the NAS’s USB ports. You can copy from the USB drive to the NAS, from the NAS to the USB drive, or set up a two-way sync. The feature is designed for unattended backups: plug in a drive, and the copy starts immediately if you have configured it that way.

The copy jobs are defined per USB device. Each USB drive can have its own set of rules, so a drive labeled “Backup” can copy a specific folder to the NAS, while another drive labeled “Deliver” copies a different NAS folder to the drive. The USB Copy app remembers which device is which by its volume ID, not by the drive letter or name.

Setting Up a Copy Job

Before you start, make sure the USB Copy package is installed. It is usually pre-installed on recent DSM versions, but you can check in Package Center. Then follow these steps:

Connect the external drive to a USB port on the Synology NAS. Wait a few seconds for the drive to appear in File Station.
Open the USB Copy application from the DSM main menu. If you don’t see it, go to Package Center and install it.
Click Create to start a new copy job.
Choose the copy mode: Copy from USB, Copy to USB, or Sync.
Select the source folder and the destination folder. For example, for “Copy to USB,” pick a folder on the NAS as the source and the USB drive’s root or a subfolder as the destination.
Set the schedule: run once immediately, or on a daily/weekly schedule. You can also choose to copy only when the drive is plugged in.
Decide whether to delete files in the destination that are not in the source (only available in Sync mode). For a simple copy, leave this unchecked.
Click OK to save the job. The copy starts according to your schedule, or immediately if you chose that option.

You can create multiple jobs for the same drive, but they cannot run at the same time. If two jobs conflict, the second one waits until the first finishes.

Copy Modes Explained

USB Copy offers three modes, and the difference matters for how files are handled:

Copy from USB: Files on the USB drive are copied to the NAS. The USB drive keeps its files. This is useful for offloading photos from a camera card or collecting files from a colleague’s drive.
Copy to USB: Files on the NAS are copied to the USB drive. The USB drive’s existing files are left alone unless they have the same name, in which case they are overwritten (depending on the overwrite setting). This is the typical backup mode.
Sync: This is a two-way or one-way synchronization. In Sync mode, you choose a direction. Files deleted on the source are deleted on the destination, and files changed are updated. This is not a simple copy; it mirrors the source folder exactly.

For a straightforward backup, “Copy to USB” is the safest choice because it does not delete anything on the external drive. Sync mode is more convenient but riskier if you accidentally delete a file on the NAS, because that deletion will propagate to the backup.

Choosing the Right External Drive

Not all USB drives work equally well with a Synology NAS. The NAS supports USB 3.0 and USB 2.0 drives, but the file system matters more than the brand. The NAS can read and write to drives formatted as ext4, exFAT, FAT32, and NTFS (with the exFAT package installed for exFAT). For a backup drive that stays connected to the NAS, ext4 is the most reliable because it preserves Linux file permissions and handles large files well. However, if you need to plug the drive into a Windows PC later, NTFS or exFAT is more convenient.

Drive size is also a consideration. The NAS will copy files until the drive is full, so choose a drive larger than the total size of the data you plan to copy. If you are using a USB hub, make sure it is powered; a bus-powered hub may not supply enough power for a 2.5-inch external drive, causing it to disconnect mid-copy.

Common Problems and Fixes

USB Copy is generally reliable, but a few issues come up regularly:

Drive not recognized: If the drive does not appear in File Station, check the file system. A drive formatted as APFS (Mac) or a RAW partition will not be recognized. Reformat the drive to exFAT or ext4 using a computer first.
Copy job does not start: The USB Copy app may not have permission to access the source or destination folder. Go to Control Panel > Shared Folder, select the folder, and edit its permissions to allow the USB Copy service (usually under the “User” tab, add the “usbcopy” user with read/write access).
Copy stops halfway: This is often due to a loose USB connection or a drive that goes to sleep. Try a different USB port or a shorter cable. If the drive has its own power supply, make sure it is plugged in.
Files are missing after copy: USB Copy does not verify checksums by default. If a file is corrupted during transfer, it will be copied as-is. For critical data, consider using Hyper Backup instead, which includes integrity checking.
USB Copy app is not available: On some newer DSM versions, USB Copy is replaced by the “USB Copy” function within the “External Devices” section of Control Panel. Check there if you cannot find the app.

USB Copy vs. Hyper Backup

USB Copy is a simple file copier. It copies files and folders, but it does not create versioned backups, compress data, or encrypt it. Hyper Backup is Synology’s advanced backup tool, and it can back up to an external USB drive as well. Hyper Backup offers deduplication, versioning, and encryption, but it stores data in a proprietary format that you cannot browse directly on the drive. If you want to see your files as normal files on the external drive, USB Copy is the right tool. If you need version history and data integrity checks, Hyper Backup is better.

Many users use both: USB Copy for a quick monthly copy of important files, and Hyper Backup for a daily incremental backup with versioning. That combination gives you both a browsable archive and a restore point in case of accidental deletion or ransomware.

Safety and Best Practices

Before relying on USB Copy for your only backup, consider these points:

Always eject the drive properly. In DSM, go to the external devices icon and click “Eject” before unplugging the drive. Unplugging mid-write can corrupt the file system.
Test a restore. A backup is only useful if you can read the files back. After the first copy, open a few files from the external drive to confirm they are not corrupted.
Keep a second copy. USB Copy is a single-copy operation. If the external drive fails, you lose the backup. For important data, use the 3-2-1 rule: three copies, on two different media, one offsite.
Check the log. USB Copy writes a log of each job. Review it after a scheduled copy to see if any files failed to copy.
Be aware of the overwrite setting. In “Copy to USB” mode, if a file with the same name exists on the destination, it will be overwritten. If you want to keep old versions, enable the “Keep versions” option or use a different destination folder each time.

Frequently Asked Questions

Can I copy files from the NAS to a USB drive without installing anything? Yes, on most DSM versions USB Copy is pre-installed. If it is not, you can install it from Package Center for free. You can also manually copy files via File Station by dragging them to the USB drive, but that does not run automatically.

Does USB Copy work with a USB hub? It can, but a powered hub is strongly recommended. A passive hub may not provide enough power for the drive, causing disconnections. If you have issues, connect the drive directly to the NAS.

Can I schedule a USB copy to run every night? Yes. In the copy job settings, you can set a daily or weekly schedule. The NAS must be powered on at the scheduled time. If the drive is not connected at that time, the job will be skipped and will not run later unless you set it to run on plug-in.

What happens if the USB drive is full during a copy? The copy stops and the log records an error. Files that were already copied remain on the drive. You need to free up space or use a larger drive, then run the job again.

Can I copy from a USB drive to a specific shared folder? Yes. When creating a “Copy from USB” job, you select the destination folder on the NAS. It can be any shared folder, including one on a different volume or RAID array.

Is USB Copy the same as a RAID backup? No. RAID protects against a single disk failure in the NAS, but it does not protect against accidental deletion, ransomware, or a fire. USB Copy to an external drive is a separate backup, which is a good complement to RAID.

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