Disable SELinux

 If you get the following error when running ./db2prereqcheck

DBT3563E  The db2prereqcheck utility determined that SELinux is enabled, which is not supported with GPFS.

Do the following:

Disabling SELinux

1. If editing the config file, Open the /etc/selinux/config file (in some systems, the /etc/sysconfig/selinux file).
2. Change the line SELINUX=enforcing to SELINUX=permissive.
3. Save and close the file.
4. Reboot your system.

For more details on what SELinux is:

https://www.computernetworkingnotes.com/rhce-study-guide/selinux-explained-with-examples-in-easy-language.html