Redhat has recently released RHEL7 Operating system. Some of the Changes in RHEL7 are listed below as compare with RHEL 6 . Default root file system is XFS Linux 3.10 kernel. A new systemctl command replaces chkconfig and service, although scripts allow you to still use the legacy commands. Docker: The biggest new addition to RHEL 7 is tight integration of Docker, the explosively popular application-virtualization technology.