sudo sed -i 's/SELINUX=.*/SELINUX=enforcing/' /etc/selinux/config
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===== Permissive =====
sudo sed -i 's/SELINUX=.*/SELINUX=permissive/' /etc/selinux/config
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Reboot
During shutdown all of the files on the system will be labeled. This may take some time depending on how many files you have and disk speed.