First step is to check whether you actually have multiple versions of the same package installed, or just that RPM/Yum think so, ie. does the command:
rpm -q glibc
report one or more packages?
If the former, the you can probably fix the problem by a clean and reset of both the RPM and Yum package data (which is harmless in any event):
# Remove the RPM package DB: rm -f /var/lib/rpm/__db.* # Rebuild the RPM package DB: rpmdb --rebuilddb # Clear the Yum cache: yum clean all # Rebuild the Yum package data (and check for updates): yum check-update
If the latter, then try the following:
# Install yum-utils (if you don't have it already): yum install yum-utils # Clean up duplicate packages # NOTE: I'd recommend a review of the Man page and use of the information options first: package-cleanup --cleandupes
HTH,