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When you insert a USB flash drive, Ubuntu mounts its usable storage: it makes the files available at a location the Files application can open.
Unmounting or ejecting ends that connection cleanly. The physical device remains plugged in until you remove it.
Identify the drive before opening it
Insert the USB and open Files. The device should appear in the sidebar, often using its volume label. Ubuntu may also show a notification.
Match more than one clue:
- The label or manufacturer name.
- Approximate capacity.
- The fact that it appeared after insertion.
- The files you expect it to contain.
Do not identify a device from one letter or device name alone. Path 1 explains why names such as /dev/sda can refer to different physical devices on different boots.
Select the sidebar entry. Files shows the mounted drive’s contents.
Copy a practice file to the USB
Use a small disposable file for the first transfer.
- Open its folder in Home.
- Select the file and choose Copy, or press
Ctrl+C. - Select the USB in the sidebar.
- Choose Paste, or press
Ctrl+V. - Wait for any progress indicator to finish.
- Confirm that the filename appears on the USB.
Open the copied file from the USB if it is safe to do so. This extra check confirms more than the disappearance of a progress message.
Eject before unplugging
Select the eject icon beside the device in the Files sidebar, or use the device’s context menu and choose Eject.
Wait until the sidebar entry disappears or Ubuntu reports that the drive can be removed. Only then unplug it.
Why the wait? A copy can appear finished on screen while Ubuntu is still writing buffered data to the slower device. Pulling it out at that moment can damage the new file or the drive’s filesystem.
Filesystem compatibility in plain language
A filesystem is the structure a storage device uses to organize files and folders.
- FAT32 works with many devices but has limits, including a maximum size for one file.
- exFAT is commonly useful for larger files shared between current operating systems.
- NTFS is common on Windows drives and can often be read and written by Ubuntu.
Compatibility depends on the device, operating system, and enabled support. You do not need to reformat a working drive merely because its filesystem name is unfamiliar.
Formatting erases the selected filesystem. That is a separate, destructive task and is not part of this lesson.
Installation USBs can look unusual
An Ubuntu installer USB is still removable storage, but writing the installation image creates a special bootable layout. Windows or Ubuntu may show several partitions, unexpected capacity, or files you did not create.
Do not format it to make the view look ordinary while it is still needed for installation or recovery. To recreate one, return to the published Ubuntu bootable USB lessons.
Safely use an external drive checklist
Before unplugging external storage
- The correct device was identified by label, capacity, and context.
- Every required copy operation finished.
- The destination contains the expected files.
- No file on the device is open in another application.
- Eject completed and the device disappeared from Files.
Common mistakes and recovery
Copying onto the wrong removable device. Stop, inspect each label and capacity, then delete only the accidental copy after confirming it is yours.
Unplugging as soon as the filename appears. Wait for the transfer and eject confirmation.
Forcing eject while a document is open. Cancel, close the document, and eject again.
Assuming a Windows-formatted USB cannot work. Try opening and copying a harmless file before changing its filesystem.
Formatting an installer USB after an unfamiliar prompt. Cancel the prompt if the installer is still needed. Path 1’s USB guidance explains the unusual layout.
Practice
Knowledge check
When is it safe to remove the USB?
Describe the evidence you need after copying a file. Include what to do if Ubuntu says the volume is busy.
What to learn next
You can now work with personal and removable files graphically. Continue to Ubuntu Settings for Beginners for a guided map of the controls that change the system.