glibc version support

Are there still issues around particular glibc versions? I know that is part of why we don't support some RHEL/CentOS 7 releases. I have a customer still on RHEL 6.7 and wonder if glibc-2.12-1.212.el6 is too old to work well with Vertica 9.1.1-5 and later. Thanks for any advice!