“Device is busy”: This warning signal indicates that the device you are trying to unmount is currently in use by the system or another process. You will need to stop the process using the device before you can safely unmount it.

“Target is busy”: This warning signal is similar to “Device is busy” and indicates that the target directory you are trying to unmount is currently in use. You will need to make sure that no processes are accessing the target directory before unmounting it.

“Unmounting file system will cause a crash”: This warning signal indicates that unmounting the file system could cause a system crash or data loss. This could happen if important system files or processes are still using the file system. It is important to ensure that no critical processes are using the file system before unmounting it.

“Operation not permitted”: This warning signal indicates that you do not have the necessary permissions to unmount the device or directory. You will need to have root privileges or be the owner of the device or directory in order to unmount it.

“Device not mounted”: This warning signal indicates that the device or directory you are trying to unmount is not currently mounted. This could happen if there was an error during the mount process or if the device was never mounted in the first place.