Fixing a WHM update that fails to complete
This tutorial will show you the steps for fixing a WHM update that fails to complete 
Sometimes a cPanel/YUM upgrade will hang. Instead of manually trying to kill all processes, you can simply use this comand:
killall -9 rpm; killall -9 rpmq; killall -9 yum; killall -9 upcp
mv /var/lib/rpm/__db* /root (in case your YUM DB is corrupted)
rpm –rebuilddb (to rebuild your cPanel/Yum DB)
yum –exclude=kernel* -y update
yum clean all
