The Differences Between Red Hat 6 and 7

The difference between red hat 6 and 7
The difference between red hat 6 and 7

Image credit: Wonderful Engineering

How often do we see this phrase when describing a new operating system, software product, or mobile device? Perhaps the better question to ask, how often is something actually new and improved? Recently, we have seen how Windows 10 may be new, but not necessarily improved when compared to its predecessor. Smartphones are being released year after year and are most definitely new, but does moving the headphone jack (and then moving it back to its original spot) actually mean it is improved?

Now, there are times when a product can be both. Sometimes the improvements are subtle and designed to accommodate advancements in technology. Some common questions regarding the latest version of Enterprise Linux is, “We’re familiar with version 6, so why do we need to learn version 7?” or “What are the major differences between 6 and 7?” Being a system administrator myself, I know the age-old cliche can apply – if ain’t broke, don’t try to fix it; however, I believe another cliche applies – the only constant is change. The needs of users are constantly changing. The needs of developers are constantly changing because the needs of users are constantly changing. Since system administrators have to support both users and developers, the products and environments they support also changes.

“Many of the improvements streamline the relationship between the operating system, enterprise, and datacenter.”

Now, Red Hat Enterprise Linux (RHEL) 7 is most definitely new, which does not always require an enterprise-wide upgrade, but many of the improvements streamline the relationship between the operating system, enterprise, and datacenter. Red Hat lists several key features/enhancements for RHEL 7 and I will highlight some of them below:

Linux Containers

Process isolation, environment simulation, and application sandboxing are all music to the ear’s of developers. Through containers, applications can share both environments and resources, while running securely in isolation from each other. Red Hat and dotCloud collaborated on Red Hat’s platform-as-a-service (PaaS) OpenShift to enable developers to package and deploy applications to nearly any Linux environment.

Containers were not an integrated option in RHEL 6 and developers were limited to creating multiple virtual machines with different environments for each application or using libvirt to manage resource utilization. In an attempt to “reach across the aisle” between developers and operations, the majority of Red Hat customers listed the roll-out of containers on the top of their to-do lists. Developers will get their applications out faster and system administrators will not be forced to manage dozens of different environments, resources, and hardware.

Identity management

Cross-realm trust with Microsoft Active Directory is now a reality and synchronization between the two is no longer required, providing true single sign-on functionality for Active Directory user to access Linux resources.

It is no secret that the enterprise networks of today are a mixed bag of hardware, software, operating systems, and platforms and the ability to streamline the enterprise is extremely beneficial to system administrators. Through Reamld, discovering Active Directory services and joining a domain is automated.

Performance Management

System-wide performance monitoring, recording, and analysis is a vital requirement to fine-tune a system for a particular use. Through the combination of Performance Co-Pilot and Tuned, administrators can leverage pre built performance profiles or configure their own. Statistical information can be transmitted across the network via popular options such as syslogd and a user-friendly graphic interface eases analysis

PCP (no, not that PCP), Performance Co-Pilot, aims to strike the balance between performance and energy consumption. Continuing with the trend of “going green”, system administrators can reduce the carbon footprint of end-user systems, while ensuring resource-hungry critical system perform at an optimal level. RHEL 6 included performance profiles and RHEL 7 includes many additional pre built profiles.


init and runlevels have been part of the Linux operating system since the beginning, but RHEL 7 has made the full conversion to Systemd. This system and service manager is compatible with SysV, sysvinit, and Linux Standard Base (LSB) init scripts, which makes the transition smoother for administrators. The switch was due primarily to the increased usage of containers, but systemd also provides the granular control needed for the new performance management features discussed earlier, among other things. The primary advantages of systemd over init are:

  • systemd never loses initial log messages
  • systemd can respawn daemons as needed
  • systemd records runtime data (i.e., captures stdout/stderr of processes)
  • systemd doesn’t lose daemon context during runtime
  • systemd can kill all components of a service cleanly

Changing something so ingrained in all Linux flavors was met with mobs carrying pitchforks and torches, but the change was necessary to incorporate the improvements made elsewhere. From a certification perspective, this changes topics discussed in Linux+ and RHCSA, but I believe this simplifies troubleshooting, the boot process, and performance management.

Red Hat details a number of other advancements in this technology overview and the majority of them are designed to accommodate the advances made in storage capacity and network performance. Do all these features and enhancements actually equate to “new and improved”? Looking at the timeline, RHEL 6 was released in November 2010 and while age is not reason enough to make the switch to 7, system administrators know that 6 years in OS years is almost the equivalent of 15 years in human years (105 years in doggy years, if you were trying to do the math). Red Hat still prides itself on well-tested and secure technology that can be expected to last for several years and version 7 will help future-proof an organization’s enterprise network. The changes made in RHEL 7 are designed to lay the necessary foundation for the future-future iterations of the OS and missing this vital step could result in a complete breakdown in the space-time continuum….

Just kidding, but imagine making the jump from Windows XP to Windows 10!!!

Fortunately for both the system administrator and those pursuing certification, Stormwind Studios Enterprise Linux System Administration class is based entirely on the latest version of the operating system and will continue to develop the curriculum to stay on top of changes to both the production environment and certification exams.