安装：

yum -y install http://ftp.riken.jp/Linux/fedora/epel/6/i386/epel-release-6-8.noarch.rpm
cd /etc/yum.repos.d
wget http://www.hop5.in/yum/el6/hop5.repo
yum clean all
yum install hhvm

可能遇到的问题：

1.hhvm: error while loading shared libraries: liblcms2.so.2: cannot open shared object file: No such file or directory

yum install http://pkgrepo.linuxtech.net/el6/release/x86_64/liblcms2-2.4-1.el6.x86_64.rpm