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Fedora & RHEL

Change locale and keyboard layout​

Check current settings​

localectl

See available locales​

localectl list-locales

Set locale​

sudo localectl set-locale LANG=en_US.UTF-8

See available keyboard layouts​

localectl list-keymaps

Set keyboard layout​

sudo localectl set-keymap layoutCode
sudo localectl set-x11-keymap layoutCode # For the graphical environment

Delete older kernels & limit max allowed​

Install yum-utils.

sudo dnf install yum-utils

Set count as how many old kernels you want left.

package-cleanup --oldkernels --count=2

To make the amount of installed kernels permanent edit /etc/yum.conf or /etc/dnf/dnf.conf and set installonly_limit option.

installonly_limit=2

Get name of installed packages with rpm​

rpm -qa --queryformat "%{NAME}\n"

Get release version​

cat /etc/redhat-release  # On RHEL
cat /etc/fedora-release  # On Fedora
lsb_release -ir   # On any of both

Manually build kernel modules installed for current kernel​

sudo akmods --force

Network proxy​

Set proxy server using environment variables​

The http_proxy and https_proxy environment variables are used to specify proxy settings to client programs such as curl and wget.

Package repository​

Add line proxy=proxyAddress to .repo file in /etc/yum.repos.d.

Package groups​

Get available and installed groups​

dnf grouplist

List packages in group​

dnf groupinfo groupName

Install a group of packages​

sudo dnf groupinstall groupName
tip
  • Option --with-optional includes optional packages of the group too.
  • Option -x pkgName excludes pkgName.

Release upgrade using dnf​

warning

Check that no repos exist with hardcoded release version in /etc/yum.repos.d/

Update current packages and install system upgrade plugin.

sudo dnf --refresh upgrade
sudo dnf install dnf-plugin-system-upgrade

Download the newer packages. Replace xy with target version.

sudo dnf system-upgrade download --refresh --releasever=xy

Trigger the upgrade process.

sudo dnf system-upgrade reboot

Remote control with VNC over SSH​

Install VNC server​

sudo yum install tigervnc-server
note

xorg-x11 and a desktop environment need to be installed as well.

Create config. file to give access to root and another user​

Save /etc/sysconfig/vncserver with the following contents:

VNCSERVERS="0:root,1:username" # Replace username with the actual name of the user
VNCSERVERARGS[0]="-rfbport 5900"
VNCSERVERARGS[1]="-rfbport 5901"

Set VNC password​

vncpasswd # Run as each allowed user

Since the idea is to connect only over SSH, the server will be started when needed from the remote machine through SSH and the insecure ports don't need to be allowed in the firewall.

Start VNC server and tunnel from the remote workstation​

ssh user@ip 'vncserver -geometry 1280x1024 -autokill'
ssh -NL 5901:localhost:5901 user@ip

Connect with a VNC client​

localhost:5901 # or 5900
note
  • To disconnect log out from the desktop environment (vnc server is stopped automatically thanks to -autokill option) and Crtl+C the SSH tunnel.
  • Tested on RHEL 7.

RH Satellite​

Manually register existing RHEL host​

Clean previous registration data.

sudo subscription-manager clean

Get rhsm data from satellite server to register a host.

sudo rpm -Uhv http://satellite.example.com/pub/katello-ca-consumer-latest.noarch.rpm

Register host.

sudo subscription-manager register --org="orgName" --activationkey="key"
sudo subscription-manager repos --list
sudo yum install katello-agent

RH Subscription Manager​

Register host with customer portal​

sudo subscription-manager register --username userName
note

Enter password when asked or pass it with --password passwd.

Attach a subscription​

sudo subscription-manager attach --pool=pool-id

Get host subscription status​

sudo subscription-manager status

Get available subscriptions​

sudo subscription-manager list --available

List available repositories​

sudo subscription-manager repos --list

Remove current registrations​

sudo subscription-manager remove --all

Remove current registration, subscriptions and local data​

sudo subscription-manager clean

Upgrade system except kernel​

sudo dnf upgrade -x kernel*