Identified from /var/log/messages & /var/log/httpd logs, httpd service fails to start. The httpd service could not start as the Apache user was unknown.
By default when Apache httpd is installed on Linux OS, it automatically makes entry to /etc/passwd and /etc/group files.
Example:
/etc/passwd
apache:x:48:48:Apache:/usr/share/httpd:/sbin/nologin
/etc/group
apache:x:48:
In this scenario, user had been set up in LDAP on the Linux server where NCM is installed, hence if LDAP is not yet running then Apache fails and therefore impacts NCM / vcmaster services. This is environmental / Linux OS level configuration issue.
To resolve this issue, add apache user and apache group to /etc/passwd and /etc/group files. Use the UID/GID and home folder that was in LDAP.
Example:
/etc/passwd
apache:x:64500:64500:Apache:/home/apache:/sbin/nologin
/etc/group
apache:x:64500:
After making the above changes, save & close the files, restart the Linux VM.
This is a known issue on Linux 7 OS. Refer https://access.redhat.com/solutions/1180103 for more details on the same.