Comparison Between RHEL 8 vs RHEL 7 vs RHEL 6

Between RHEL 6, RHEL 7 and RHEL 8 there are numerous changes in tools, commands and workflows.

Included the possible difference between them in this article.

We have gone through several Red Hat articles and RHEL 6, 7 and 8 Release Notes to gather this information.

We have added a comparison table based on category.

It has five categories and each type contains related information.

This will give you a comparison between RHEL8 vs RHEL7 vs RHEL6.

If we missed any points, please update your query in the comment section so that we can update the article.

It will help others to know about it.

Red Hat Enterprise Linux 8 (Ootpa) is based on Fedora 28 and modular software repository, curated 3rd-party software repositories notable new features.

This release provides a stable, secure and good foundation to deploy Linux containers to public and private clouds, which support customer’s workloads and operations seamlessly.

General Information

S.NoDescriptionRHEL 8RHEL 7RHEL 6
1General Availability Date14-Nov-1810-Jun-1410-Nov-10
2Code NameOotpaMaipoSantiago
3Kernel Version4.183.10.0-1232.6.32-71
4End of Full SupportMay-2024Q4 201910-May-16
5End of Maintenance Support 1N/AQ4 202010-May-17
6End of Maintenance Support 2May-202930-Jun-202430-Nov-20
7End of Extended Life cycle SupportTBDN/A30-Jun-24
8Last Minor ReleaseTBD7.76.10

Boot Process Related Changes

S.NoDescriptionRHEL 8RHEL 7RHEL 6
1Boot Loader: The GRUB2 looks very similar to GRUB but there are many features added.GRUB 2Legacy GRUB
2Runlevel: Runlevels are referred as target but there is no difference but they merged runlevel 2,3,4 into one.runlevel0.target -> poweroff.target
runlevel1.target -> rescue.target
runlevel2.target -> multi-user.target
runlevel3.target -> multi-user.target
runlevel4.target -> multi-user.target
runlevel5.target -> graphical.target
runlevel6.target -> reboot.target
runlevel 0
runlevel 1
runlevel 2
runlevel 3
runlevel 4
runlevel 5
runlevel 6
3To view runlevel/targetsystemctl get-defaultrunlevel
4To change runlevel/targetsystemctl isolate [Name.target]init [runlevel]
5To configure default runlevel/targetsystemctl set-default [Name.target]/etc/inittab
6To break root password or Boot into single user modeAppend rd.break or init=/bin/bash to kernel cmdlineAppend 1 or s or init=/bin/bash to kernel cmdline
7KDUMPKdump is enabled by default and will run without any problems if the system has too much RAM.Kdump is enabled by default and will run without any problems if the system has too much RAM (up to 3 TB).Kdump is enabled by default and will run without any problems if the system has too much RAM.

Major Package Changes

S.NoDescriptionRHEL 8RHEL 7RHEL 6
1System Manager: Systemd is a new init system and system manager which was adapted by most of the major distribution.systemdupstart
2Service Managersystemctl commandservice command
3Enable Service on Bootsystemctl commandchkconfig
4Network Time SynchronizationOnly Chrony (faster time sync and useful for the systems which are not online all the time)It supports Chrony and ntpntp
5Network BondingTeamdBonding
6To view ports/socketsss and lsofnetstat, ss and lsof
7Cluster Resource ManagerPacemakerRgmanager
8GUI Interface (Desktop)Gnome 3.28Gnome 3Gnome 2
9Default Display ServerWaylandX.OrgX.Org
10Default DatabaseMySQL 8.0, MariaDB 10.3, PostgreSQL 10 and 9.6, and Redis 5.0MariaDBMySQL
11Default FirewallFirewalld, it uses nftables framework in the backendFirewalld, it uses Iptables framework in the backendIptables
12Temporary Files Managementsystemd-tmpfilestmpwatch
13Load Balancer TechnologyKeepalived and HAProxyPiranha
14PythonPython 3Python 2.7.5Python 2.0
15PHPPHP 7.2PHP 5.4PHP 5.3
16CompilerGCC 8.2.1GCC 4.8.2GCC 4.4

File System Related Changes

S.NoDescriptionRHEL 8RHEL 7RHEL 6
1Default File SystemXFSEXT4
2File System Checkxfs_repairxfs_repaire2fsck
3File System Extend: xfs_growfs (This doesn’t allow you to reduce a filesystem)xfs_growfsxfs_growfsresize2fs

Other Changes

S.NoDescriptionRHEL 8RHEL 7RHEL 6
1First Process owned bysystemd (PID 1)systemd (PID 1)init (PID 1)
2Network Interface NameenpXXX (enp0s3)enpXXX (enp0s3)eth0
3Host Name ChangeIt needs to be defined in /etc/hostname file/etc/hostnameIt’s defined in /etc/sysconfig/network file
4UID Allocation Change0-999 UIDs are reserved for system and application users.0-9990-499
5Max Supported (Individual) File & Filesystem SizeXFS= 500TB
XFS= 1024TB
XFS= 500TB
XFS= 500TB
EXT4= 16TB
EXT4= 16TB
6ISO ImageOnly 64-BitOnly 64-Bit32-Bit and 64-Bit
7Mount Options ChangeBy default user_xattr and acl mount options are enabledBy default user_xattr and acl mount options are enabledNeed to enable them manually
8Default ReposRepo ID: rhel-8-for-x86_64-appstream-rpms
Repo Name: Red Hat Enterprise Linux 8 for x86_64 – AppStream (RPMs)
Repo ID: rhel-8-for-x86_64-baseos-rpms
Repo Name: Red Hat Enterprise Linux 8 for x86_64 – BaseOS (RPMs)
Repo ID: rhel-7-server-rpms
Repo Name: Red Hat Enterprise Linux 7 Server (RPMs)
Repo ID: rhel-6-server-rpms
Repo Name: Red Hat Enterprise Linux 6 Server (RPMs)
9Package ManagementBy default both are installed, YUM symbolic link to DNFBy default only YUM and DNF can be installed from the Extra repoOnly YUM
10Max. RAM Supported24 TB on x86_64 architecture12 TB on x86_64 architecture12 TB on x86_64 architecture
11Directories ChangeDirectories /bin, /sbin, /lib and /lib64 are now all under the /usr directoryAll these under the /usr directoryAll these under the / directory
12Loggingrsyslog and journalrsyslog and journalOnly rsyslog
13Minimum required disk space10GB minimum, 20GB recommended10GB minimum, 20GB recommended1GB minimum, 5GB recommended
14Is the upgrade possible?YesYes, RHEL 7.7 to RHEL 8Yes, RHEL 6.10 to RHEL 7.7
15Virtual Machines Managementcockpitvirt-managervirt-manager

Magesh Maruthamuthu

Love to play with all Linux distribution

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