As we already know, files and folders in the /tmp folder is temporary and will be cleared after the system reboot. But We can disable this feature by modifying the system configuration and make the folder /tmp as permanent storage.
This cleanup is performed on the basis of TMPTIME value configured in system settings. To stop the default behavior we need to increase TMPTIME to a sufficient value.
On Debian-like systems: TMPTIME is defined in the file '/etc/default/rcS'.
On RedHat-like systems: For RHEL6, TMPTIME is defined in the file '/etc/cron.daily/tmpwatch' and For RHEL7, TMPTIME is defined in the file '/usr/lib/tmpfiles.d/tmp.conf', called by systemd-tmpfiles-clean.service.
Note: '0' means always, -1 or 'infinite' disables the feature