System and command changes between RHEL 6 and RHEL 7
Between RHEL6 and RHEL7 there are a number of changes to tools, commands, and workflows. Changes that are likely to affect common administrative tasks are listed here:
- Anaconda RHEL installer completely redesigned1
- Legacy GRUB boot loader replaced by GRUB22
- Procedure for bypassing root password prompt at boot completely different3
- SysV init system and all related tools replaced by systemd4
- ext4 replaced by xfs as default filesystem type5
- Directories /bin, /sbin, /lib and /lib64 are now all under the /usr directory6
- Network interfaces have a new naming scheme based on physical device location (e.g., eth0 might become enp0s3)7
ntpd
replaced bychronyd
as the default network time protocol daemon8- GNOME2 replaced by GNOME3 as default desktop environment9
- System registration and subscription now handled exclusively with Red Hat Subscription Management (RHSM)10
- MySQL replaced by Mariadb11
tgtd
replaced bytargetcli
12- High Availability Add-On: RGManager removed as resource-management option (in favor of Pacemaker); all CMAN features merged into Corosync (
qdiskd
replaced by votequorum plugin); all tools unified intopcs
13 ifconfig
androute
commands are further deprecated in favor ofip
netstat
further deprecated in favor ofss
- System user UID range extended from 0-499 to 0-999
locate
no longer available by default; (available as mlocate package)nc
(netcat) replaced bynmap-ncat
See footnotes for additional detail about these changes.
Administrative command and config-file changes
System Basics
Task | RHEL6 | RHEL7 |
---|---|---|
View RH subscription information | /etc/sysconfig/rhn/systemid subscription-manager identity |
subscription-manager identity |
Configure RH subscription | rhn_register rhnreg_ks subscription-manager |
subscription-manager14 rhn_register15 |
Basic Configuration
Task | RHEL6 | RHEL7 |
---|---|---|
Graphical configuration tools | system-config-* | gnome-control-center |
Configure network | system-config-network | nmcli nmtui nm-connection-editor |
Configure system language | system-config-language | localectl |
Configure system time and date | system-config-date date |
timedatectl date |
Synchronize time and date | ntpdate /etc/ntp.conf |
ntpdate /etc/chrony.conf |
Configure keyboard | system-config-keyboard | localectl |
Jobs and services
Task | RHEL6 | RHEL7 |
---|---|---|
List all services | chkconfig ls /etc/init.d/ |
systemctl -at service ls /{usr/lib,etc}/systemd/system/*.service |
List running services | service –status-all | systemctl -t service –state=active |
Start/stop a service | service name start service name stop |
systemctl start name.service systemctl stop name.service |
Enable/disable a service | chkconfig name on chkconfig name off |
systemctl enable name.service systemctl disable name.service |
Check if service enabled | chkconfig name | systemctl is-enabled name |
View service status | service name status | systemctl status name.service |
Create service file or change config | chkconfig –add | systemctl daemon-reload |
View runlevel/target | runlevel | systemctl get-default |
Change runlevel/target | init runlevel | systemctl isolate name.target init runlevel |
Configure logging | /etc/rsyslog.conf | /etc/rsyslog.conf /etc/rsyslog.d/*.conf /var/log/journal/ /etc/systemd/journald.conf |
View logs | /var/log/ | /var/log/ journalctl |
Kernel, boot, and hardware
Task | RHEL6 | RHEL7 |
---|---|---|
Bypass root password prompt at boot | append 1 or s or init=/bin/bash to kernel cmdline | append rd.break or init=/bin/bash to kernel cmdline |
Shut down system | shutdown | systemctl shutdown |
Power off system | poweroff | systemctl poweroff |
Halt system | halt | systemctl halt |
Reboot system | reboot | systemctl reboot |
Configure default runlevel/target | /etc/inittab | systemctl set-default |
Configure GRUB bootloader | /boot/grub/grub.conf | /etc/default/grub grub2-mkconfig grub-set-default |
Software management
Task | RHEL6 | RHEL7 |
---|---|---|
Install software | yum install yum groupinstall |
yum install yum group install |
View software info | yum info yum groupinfo |
yum info yum group info |
File systems, volumes, and disks
Task | RHEL6 | RHEL7 |
---|---|---|
Create/modify disk partitions | fdisk parted |
fdisk parted gdisk |
Default file system | ext4 | xfs |
Enlarge volumes formatted with default filesystem | vgextend lvextend resize2fs |
vgextend lvextend xfs_growfs |
Networking
Task | RHEL6 | RHEL7 |
---|---|---|
Configure name resolution | /etc/hosts /etc/resolv.conf |
/etc/hosts /etc/resolv.conf nmcli con mod |
Configure hostname | /etc/sysconfig/network | /etc/hostname hostnamectl nmtui |
View network interface info | ip addr ifconfig brctl |
ip addr nmcli dev show teamdctl brctl bridge |
Configure network interface | /etc/sysconfig/network-scripts/ifcfg-* | /etc/sysconfig/network-scripts/ifcfg-* nmcli con [add|mod|edit] nmtui nm-connection-editor |
Configure firewall | iptables & ip6tables /etc/sysconfig/ip*tables system-config-firewall |
firewall-cmd firewall-config |
View ports/sockets | netstat ss lsof |
ss lsof |
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Migration Planning Guide: New Installer and Installation Guide ↩
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Migration Planning Guide: New Boot Loader and System Administrator’s Guide: Working with the GRUB 2 Boot Loader ↩
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Some systemd-related commands do not return output. Further information on systemd available at Migration Planning Guide: New Init System and System Administrator’s Guide: Managing Services with systemd ↩
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Migration Planning Guide: New Default File System: XFS and Storage Administration Guide: The XFS File System andInstallation Guide: Reference Table for ext4 and XFS Commands ↩
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Migration Planning Guide: New Network Naming Schema and Networking Guide: Consistent Network Device Naming ↩
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System Administrator’s Guide: Configuring NTP Using the chrony Suite ↩
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Migration Planning Guide: Desktop and Desktop Migration and Administration Guide: ↩
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Migration Planning Guide: Target Management with targetcli ↩
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High Availability Add-On Overview: Overview of Differences Between Releases ↩
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subscription-manager is used for Satellite 6, Satellite 5.6 with SAM and newer, and Red Hat’s CDN. ↩
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RHN tools are deprecated on Red Hat Enterprise Linux 7. rhn_register should be used for Satellite server 5.6 and newer only. For details, see: Satellite 5.6: unable to register RHEL 7 client system due to rhn-setup package not included in Minimal installation ↩