Centos 7 is normally managed by the ocs 2.1 agent without lsb_release.
But there is a bug:
in the following file /usr/share/perl5/vendor_perl/Ocsinventory/Agent/Backend/OS/Linux/Distro/NonLSB/CentOS.pm, /etc/redhat_release is discarded if it is a link. But it should not since in Centos this file is a link.
To solve this problem it is necessary to remove the lines 7 and 8 of CentOS.pm file.