label centos741708x8664
 	MENU LABEL CentOS 7.4.1708 x86_64
 	KERNEL /pxeknife/installers/centos/7.4.1708/x86_64/vmlinuz 
 	APPEND reiserfs jfs xfs btrfs initrd=/pxeknife/installers/centos/7.4.1708/x86_64/initrd.img method=http://archive.kernel.org/centos-vault//7.4.1708/os/x86_64/ ip=dhcp