I already tried "yum install gcc-c++" Result is this: # yum install gcc-c++ Loaded plugins: enabled_repos_upload, fastestmirror, imgbased-persist, package_upload, product-id, search-disabled-repos, subscription-manager, vdsmupgrade This system is not registered with an entitlement server. You can use subscription-manager to register. Loading mirror speeds from cached hostfile * ovirt-4.2-epel: mirror.seas.harvard.edu No package gcc-c++ available. Error: Nothing to do Uploading Enabled Repositories Report Loaded plugins: fastestmirror, product-id, subscription-manager This system is not registered with an entitlement server. You can use subscription-manager to register. Cannot upload enabled repos report, is this client registered?