problem : LDAP Services not working on the Cluster setup Details LDAP Server 1 - 192.168.10.91 ( ldap1.pbifmsiwdms.pjb ) LDAP Server 2 - 192.168.10.96 ( ldap2.pbifmsiwdms.pjb ) Cluster IP - 192.168.10.98 Diagnosis Process and resolution Check Cluster Status on LDAP 1 # clustat Service not running Check Cluster Status on LDAP 2 #clustat Cluster Status for LdapCluster @ Sat May 21 10:02:44 2016 Member Status: Quorate Member Name ID Status ------ ---- ---- ------ ldap1.pbifmsiwdms.pjb 1 Offline ldap2.pbifmsiwdms.pjb 2 Online, Local But Services were not showing On LDAP1 Started the cman and rgmanager services /etc/init.d/cman start /etc/init.d/rgmanager start Checked in /var/log/messages for any error . cman and rgmanager Services started successfully . Checked the cluster status #clustat Cluster Status for LdapCluster @ Sat May 21 10:02:44 2016 Member Status: Quorate Member Name ID Status ------ ---- ---- ------ ldap1.pbifmsiwdms.pjb 1 Online, Local ldap2.pbifmsiwdms.pjb 2 Online But Services were still not showing. We have to enable the service manually #clusvcadm -e dummy_httpd -m ldap1.pbifmsiwdms.pjb ( where dummy_httpd is the service named defined in /etc/cluster/cluster.conf ) But Service dummy_httpd failled . Checked the log and found /etc/init.d/httpd , could not start . Tried to start httpd service via "/etc/init.d/httpd start" , but failed . Checked the log i.e /var/log/httpd/error_log and found [Sat May 21 10:14:45 2016] [error] Unable to verify certificate 'Server-Cert'. Add "NSSEnforceValidCerts off" to nss.conf so the server can start until the problem can be resolved. We added NSSEnforceValidCerts off in /etc/httpd/conf.d/nss.conf in virtualHost context . Checked the httpd service via starting it on the cli , it worked successfully . Then we stopped this service as it is controlled by cluster process. We enabled the service manually again #clusvcadm -e dummy_httpd -m ldap1.pbifmsiwdms.pjb The services started successfully . [root@ldap1 ~]# clustat Cluster Status for LdapCluster @ Sat May 21 10:43:43 2016 Member Status: Quorate Member Name ID Status ------ ---- ---- ------ ldap1.pbifmsiwdms.pjb 1 Online, Local, rgmanager ldap2.pbifmsiwdms.pjb 2 Online Service Name Owner (Last) State ------- ---- ----- ------ ----- service:dummy_httpd ldap1.pbifmsiwdms.pjb started Now Cluster IP is visible and LDAP is successfully accessed .