I had a very similar problem with my CentOS installation.
The installation documentation says that SELinux in permissive mode will work. But in my case it absolutely did not. After disabling SELinux entirely, recreating the database and .config folder, the installation proceeded fully.
I am running Cells with SElinux enabled (enforcing) on all instances. Prior to running the installer and after running through the installer one should issue
restorecon -FRv /
to ensure all contexts are set correctly (elsewhere in the file system). I have had no issues after following this procedure.
If you experience issues ans suspect SElinux to be the cause, always check the audit logs - there may be a simple reason that can be easily fixed by running restorecon, changing some settings or, in rare cases, by altering the policy.