Sometime s it is so irritating when you want to remove some thing in linux and you find .nfsXXXXX file “Cannot be removed: Device or resource busy”. ps command would not help in these scenarios to know what is actually using it. lsof is a command in linux to figure the open files. The output of this command is the list of files that open and used by the processes, the process name and PID of the process that is using the file. To remove .nfsXXXX files. Run lsof command Find the processID of the process that is using .nfsXXXX file. Kill the process. Remove the .nfsXXX file using rm command.