System Configuration Issues

This page covers host-level configuration issues.

SELinux Causes Service Failure

Symptom: Services fail on RHEL after deployment due to SELinux denials.

Solution: Check SELinux audit logs for denials:

sudo ausearch -m AVC -ts recent

The init_server role sets disable_selinux: true by default. If you changed this setting, review the audit logs and create the appropriate SELinux policy. A system reboot may be required after disabling SELinux.

SSH Key Problems

Symptom: PgBackRest SSH backup fails because of key authentication errors.

Solution: Verify that the postgres OS user's SSH key exists and has correct permissions:

sudo -u postgres ls -la ~/.ssh/

Verify that the public key appears in the authorized_keys file on the backup server:

sudo -u backup-user cat ~/.ssh/authorized_keys

Hostname Resolution Fails

Symptom: Nodes cannot reach each other by hostname.

Solution: Verify that manage_host_file is true so the collection populates /etc/hosts on every node. If external DNS handles resolution, confirm that each hostname resolves correctly:

nslookup node1.example.com