I helped set up a cluster couple of years ago. The server OS has not been upgraded ever since because it requires rebuilding the whole system and we don’t have the time for it. The OS is still CentOS 6.5. There is a problem with yum for a while now. Some yum commands would result in segmentation fault. I finally got around to fix the problem. My first clue is this entry in the /var/log/messages.
kernel: genpkgmetadata.: segfault at 3000000000 ip 000000302ef29170 sp 00007fff3b2603e8 error 4 in libc-2.12.so[302ee00000+18a000]
Using this clue as the search term in Google, I found a solution in the RedHat solutions database. The suggestion is to upgrade the libxml2 to at least libxml2-2.7.6-14.el6_5.2.x86_64. If you have subscription to RedHat, you can look for the solution 32778 for details. Anyway, I was able to use
yum install libxml2
to fix the problem. If your yum install command does not work, just download the latest libxml2 rpm and install it manually.