RHEL 8 vs RHEL 7 vs RHEL 6之间的比较（英文说明）

1

General Availability Date

14-Nov-18

10-Jun-14

10-Nov-10

2

Code Name

Ootpa

Maipo

Santiago

3

Kernel Version

4.18

3.10.0-123

2.6.32-71

4

End of Full Support

May-2024

Q4 2019

10-May-16

5

End of Maintenance Support 1

N/A

Q4 2020

10-May-17

6

End of Maintenance Support 2

May-2029

30-Jun-2024

30-Nov-20

7

End of Extended Life cycle Support

TBD

N/A

30-Jun-24

8

Last Minor Release

TBD

7.7

6.10

1

Boot Loader: The GRUB2 looks very similar to GRUB but there are many features added.

GRUB 2

Legacy GRUB

2

Runlevel: 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

3

To view runlevel/target

systemctl get-default

runlevel

4

To change runlevel/target

systemctl isolate [Name.target]

init [runlevel]

5

To configure default runlevel/target

systemctl set-default [Name.target]

/etc/inittab

6

To break root password or Boot into single user mode

Append rd.break or init=/bin/bash to kernel cmdline

Append 1 or s or init=/bin/bash to kernel cmdline

7

KDUMP

Kdump 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.

1

System Manager: Systemd is a new init system and system manager which was adapted by most of the major distribution.

systemd

upstart

2

Service Manager

systemctl command

service command

3

Enable Service on Boot

systemctl command

chkconfig

4

Network Time Synchronization

Only Chrony (faster time sync and useful for the systems which are not online all the time)

It supports Chrony and ntp

ntp

5

Network Bonding

Teamd

Bonding

6

To view ports/sockets

ss and lsof

netstat, ss and lsof

7

Cluster Resource Manager

Pacemaker

Rgmanager

8

GUI Interface (Desktop)

Gnome 3.28

Gnome 3

Gnome 2

9

Default Display Server

Wayland

X.Org

X.Org

10

Default Database

MySQL 8.0, MariaDB 10.3, PostgreSQL 10 and 9.6, and Redis 5.0

MariaDB

MySQL

11

Default Firewall

Firewalld, it uses nftables framework in the backend

Firewalld, it uses Iptables framework in the backend

Iptables

12

Temporary Files Management

systemd-tmpfiles

tmpwatch

13

Load Balancer Technology

Keepalived and HAProxy

Piranha

14

Python

Python 3

Python 2.7.5

Python 2.0

15

PHP

PHP 7.2

PHP 5.4

PHP 5.3

16

Compiler

GCC 8.2.1

GCC 4.8.2

GCC 4.4

1

Default File System

XFS

EXT4

2

File System Check

xfs_repair

xfs_repair

e2fsck

3

File System Extend: xfs_growfs (This doesn’t allow you to reduce a filesystem)

xfs_growfs

xfs_growfs

resize2fs

1

First Process owned by

systemd (PID 1)

systemd (PID 1)

init (PID 1)

2

Network Interface Name

enpXXX (enp0s3)

enpXXX (enp0s3)

eth0

3

Host Name Change

It needs to be defined in /etc/hostname file

/etc/hostname

It’s defined in /etc/sysconfig/network file

4

UID Allocation Change

0-999 UIDs are reserved for system and application users.

0-999

0-499

5

Max Supported (Individual) File & Filesystem Size

XFS= 500TB
XFS= 1024TB

XFS= 500TB
XFS= 500TB

EXT4= 16TB
EXT4= 16TB

6

ISO Image

Only 64-Bit

Only 64-Bit

32-Bit and 64-Bit

7

Mount Options Change

By default user_xattr and acl mount options are enabled

By default user_xattr and acl mount options are enabled

Need to enable them manually

8

Default Repos

Repo 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)

9

Package Management

By default both are installed, YUM symbolic link to DNF

By default only YUM and DNF can be installed from the Extra repo

Only YUM

10

Max. RAM Supported

24 TB on x86_64 architecture

12 TB on x86_64 architecture

12 TB on x86_64 architecture

11

Directories Change

Directories /bin, /sbin, /lib and /lib64 are now all under the /usr directory

All these under the /usr directory

All these under the / directory

12

Logging

rsyslog and journal

rsyslog and journal

Only rsyslog

13

Minimum required disk space

10GB minimum, 20GB recommended

10GB minimum, 20GB recommended

1GB minimum, 5GB recommended

14

Is the upgrade possible?

Yes

Yes, RHEL 7.7 to RHEL 8

Yes, RHEL 6.10 to RHEL 7.7

15

Virtual Machines Management

cockpit

virt-manager

virt-manager