I don’t know much about other situations, so let’s talk about the solutions for the situations I have encountered.
if you modify /proc folder, because files in /proc are not actual files, they’re an interface to lower-levels of the operating system. https://askubuntu.com/questions/167819/im-getting-fsync-failed-error-why) p>
therefore, directly use the echo command, through the shell to write in to succeed.