Red Hat Subscription Service
Once you have installed RHEL 9, register your RHEL subscription by running the following command on the terminal. The username and password are the login details to your Red Hat account.
$ sudo subscription-manager register --username=username --password=password
To confirm that the system is registered to Red Hat Subscription Management (RHSM), run the command:
$ sudo subscription-manager list --installed
Then refresh and subscribe:
$ sudo subscription-manager refresh
$ sudo subscription-manager attach --auto
Or, list the subscriptions that are available:
$ subscription-manager list --available --all
$ subscription-manager attach --pool=<POOL_ID>
Unregistering a system:
$ subscription-manager remove --all
$ subscription-manager unregister
$ subscription-manager clean
Speed Up DNF Package Manager
You can increase the download speed for installing packages using DNF by updating the maximum number of simultaneous package downloads.
Start by editing the /etc/dnf/dnf.conf file:
$ sudo nano /etc/dnf/dnf.conf
Add the following line to enable DNF parallel downloads:
max_parallel_downloads=10
Another option is to select the fastest mirror from the Fedora public mirrors by adding the following line:
fastestmirror=True
Tags: cli, dnf, fedora, rhel, package-managers, motd
Red Hat Subscripion Manager - Registering
Registering your RHEL instance with Red Hat is straightforward assuming that you already have an account:
# subscription-manager register --username <your-rh-user> --password <password>
List the available repos or just go with a default:
# subscription-manager list --available
# subscription-manager attach --auto
Then you can do your update:
# yum update
RHEL QCOW Image Password
Did you know that although you can install RHEL from an
ISO, you can also download a QCOW2 image from
Red Hat. However, when you try to start it up under
virt-manager you’ll see that it boots to a
root prompt and you don’t know what the password is. This
can be fixed by running the following from the host’s terminal:
# virt-customize -a <qcow2-image-file-name> --root-password password:<password>
How to List Installed Packages in Fedora, RHEL, CentOS
Listing installed packages with YUM:
$ sudo yum list installed
To display details about a package:
$ yum info nginx
You can cat all installed packages to a file, copy the file to another machine and duplicate the system:
$ sudo yum list installed > installed-packages.txt
$ sudo yum -y install $(cat installed-packages.txt)
List installed packages with RPM:
$ sudo rpm -qa
List them by installation date:
$ sudo rpm -qa --last
Display information about a package:
$ rpm -qi nginx