Device or resource busy

The error message Device or resource busy indicates that an operating system resource is currently in use and cannot be accessed, modified, or released at that moment. This is a low-level OS error commonly seen on Linux and Unix-like systems, but it can also surface indirectly in containers, databases, build tools, and applications that rely on the underlying filesystem or kernel resources.

When does this error occur?

  • Trying to unmount a filesystem that is still being used by a process
  • Deleting or modifying a file that is currently open by another process
  • Formatting or mounting a device that already has active I/O operations
  • Stopping or restarting services that still hold file or socket locks
  • Cleaning up build or runtime directories in use by background jobs

Root cause of Device or resource busy

At the OS level, Device or resource busy occurs when the kernel prevents an operation because the target device, file, or directory is actively referenced by one or more running processes. The kernel enforces this protection to maintain data integrity and system stability, ensuring that resources are not removed or altered while in use.

How to fix the error (step-by-step)

Linux / macOS

Identify which process is using the resource. 

lsof /path/to/resource

Alternatively, check processes using a mounted filesystem. 

fuser -v /path/to/resource

Stop or terminate the blocking process if it is safe to do so. 

kill <PID>

If the error occurs during unmount, ensure no shell or service is inside the directory. 

cd /
umount /mount/point

Docker / containers

Stop containers that are using the filesystem or volume. 

docker ps
docker stop <container_id>

Retry the operation after containers release the resource.

Java / Spring Boot

Ensure the application has fully stopped before cleaning temporary files or logs. 

ps -ef | grep java

Gracefully shut down the process and retry the operation.

Verify the fix

Re-run the original command or operation after the blocking process has been stopped. The action should complete without the Device or resource busy message, and the resource should be accessible, unmounted, or modified as expected.

Common mistakes to avoid

  • Killing critical system processes without understanding their role
  • Forcing unmounts without checking active file usage
  • Ignoring background services or cron jobs holding locks
  • Assuming the error is permission-related instead of usage-related

Quick tip

Before removing or unmounting any resource, always verify that no active process is using it to avoid unexpected failures.

FAQ

Q: Is Device or resource busy the same as a permission error?

A: No. This error means the resource is in use, not that access is denied by permissions.

Q: Can rebooting fix this error?

A: Yes, a reboot releases all locks, but it should be a last resort after identifying the blocking process.

Conclusion

The Device or resource busy error is a kernel-level protection mechanism that ensures safe resource usage. Understanding which process holds the resource is the key to resolving it effectively—explore related ROOT errors on ErrorFixHub for deeper system troubleshooting.

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