Copy Files from Synology NAS to USB Drive

Updated 6 November 2026 · Standard formula, shown below

This guide walks you through copying files from a Synology NAS to a USB drive, whether you want to back up important data, transfer files to another device, or free up space on your NAS. You’ll learn both the quick drag-and-drop method and the more robust backup task approach, along with common pitfalls and troubleshooting tips.

What You’ll Need

A Synology NAS with DSM (DiskStation Manager) installed and accessible.
A USB drive with enough free space for the files you plan to copy. It can be formatted as FAT32, exFAT, NTFS, or ext4; the NAS supports all of these.
Access to DSM as a user with read/write permissions on the source folder and the USB drive.
If you prefer command-line methods, enable SSH (optional).

Step-by-Step

Connect the USB drive to the NAS. Plug the drive into any USB port on your Synology. Wait a few seconds; DSM will detect it automatically. You’ll see a notification in the top-right corner, and the drive will appear under File Station under the USB section.
Open File Station. Log into DSM and launch File Station from the main menu (the grid icon in the top-left).
Locate your USB drive. In the left sidebar, scroll down to find USB and click the arrow to expand it. Your drive should appear with its name and capacity (e.g., USB Drive 1).
Navigate to the files you want to copy. In the main panel, browse to the folder on your NAS that contains the files. You can use the left sidebar to jump to shared folders like home or public.
Select the files or folders. Click once to select a single item. To select multiple, hold Ctrl (Windows) or Cmd (Mac) while clicking. To select a range, click the first item, hold Shift, and click the last.
Copy the items. Right-click on the selection and choose Copy (or press Ctrl+C / Cmd+C).
Navigate to the USB drive. In the left sidebar, click on your USB drive to open it. If you want to place the files in a subfolder, double-click to enter it.
Paste the files. Right-click in the empty area of the main panel and choose Paste (or press Ctrl+V / Cmd+V). A progress dialog will appear showing the transfer speed and estimated time.
Wait for the transfer to complete. Do not disconnect the USB drive during the copy. Once the progress bar reaches 100%, the files are on the drive.
Safely eject the USB drive. Right-click on the USB drive in the left sidebar and select Eject. Wait for the confirmation message before physically removing the drive.

For large or recurring transfers, you can use the Backup feature in Hyper Backup (available in Package Center) or create a File Station task to automate the copy. The manual method above works fine for one-off transfers.

Common Mistakes

Not ejecting the drive safely. Removing the USB drive while files are being written can corrupt data on the drive. Always eject through DSM first.
Copying instead of moving. If you intend to free NAS space, remember to delete the source files after verifying the copy. The copy operation leaves the originals intact.
Insufficient space on the USB drive. Check the free space before starting. DSM will show an error if the drive is full, but it’s better to verify beforehand.
File system incompatibility. If the USB drive is formatted as exFAT or NTFS, some file attributes (like permissions) may not be preserved. For a pure backup, ext4 is best, but it’s not readable on Windows without extra software.
Copying system files. Avoid copying hidden system folders (e.g., @eaDir) unless you know what they are; they can clutter the USB drive.

Tips

Use the “Copy to� option. In File Station, you can right-click a file and choose Copy to, then navigate to the USB drive. This avoids the two-step copy/paste.
Enable checksum verification. In Hyper Backup, you can enable integrity checking to ensure the copied files are identical to the originals.
Organize the USB drive. Create a folder like NAS Backup on the drive to keep things tidy.
Use a USB 3.0 port. If your Synology has USB 3.0 ports (blue), use them for faster transfer speeds, especially with large files.
Schedule backups. For regular backups, set up a Hyper Backup task to run automatically. This avoids manual copying.

Troubleshooting

USB drive not detected. Try a different USB port. Check if the drive is formatted in a supported file system (FAT32, exFAT, NTFS, ext4). If it’s a new drive, format it on a computer first. Also, check if the drive is listed under External Devices in Control Panel.
Transfer fails partway. This is often due to a loose connection or a failing USB drive. Try a different cable or port. Check the NAS system log (Main Menu > Log Center) for error messages. If the drive is overheating, let it cool down.
“Permission denied� error. Ensure your user account has read access to the source folder and write access to the USB drive. Go to Control Panel > Shared Folder, select the folder, and edit permissions.
Files are corrupted after copy. The USB drive might be faulty. Test it on a computer. Also, avoid unplugging the drive during transfer. For critical data, use Hyper Backup with integrity checking.
Transfer speed is very slow. Large numbers of small files transfer slower than a few large files. Consider zipping the files into an archive before copying. Also, ensure you’re using a USB 3.0 port and a quality cable.

Frequently Asked Questions

Can I copy files from the NAS to a USB drive using a computer?

Yes. Connect the USB drive to your computer, then use a network drive mapping (SMB) to access the NAS and copy files directly to the USB drive. The steps are similar to copying between local folders.

Does the USB drive need to be formatted in a specific way?

No, DSM supports FAT32, exFAT, NTFS, and ext4. For Windows compatibility, use NTFS or exFAT. For Mac, exFAT or FAT32. For pure NAS backup, ext4 is recommended.

Can I schedule automatic copies to a USB drive?

Yes. Use Hyper Backup (install from Package Center) to create a backup task targeting the USB drive. You can set a schedule and choose folders to back up.

Is it safe to unplug the USB drive after copying?

Always eject the drive first through DSM (right-click > Eject). This ensures all writes are flushed. Removing it without ejecting can corrupt data.

What if the USB drive is full?

DSM will show an error and stop the copy. Free up space on the drive or select fewer files. You can also split the copy into multiple sessions.

Can I copy files from the USB drive back to the NAS?

Yes, the process is identical. In File Station, navigate to the USB drive, select files, and copy them to a shared folder on the NAS.

Method: the standard formula for this calculation, rounded as each result states. See how the calculators work or report an error.