Best Fixes
Find the process or mount relationship keeping the file, directory, or device busy, then stop or detach it cleanly.
Retry only after confirming the resource is no longer actively in use.
Error Fix
How to Fix 'Device or resource busy'
Why files, mounts, and devices cannot be modified while still in use and how to identify the blocker.
This error means the target is still being used by a process, subsystem, or mount relationship. The safest fix is to identify that active user before forcing anything.
Avoid This
Do not force-unmount or kill processes casually without understanding the impact.
Do not assume permissions are the issue when the resource is actually still in use.
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