Chapter 3. Performing basic system administration tasks in the web console

In this chapter, you will learn how to perform basic system administration tasks, such as restart, shutdown, or basic configuration, using the web console.

3.1. What the RHEL 8 web console is and which tasks it can be used for

The RHEL 8 web console is an interactive server administration interface. It interacts directly with the operating system from a real Linux session in a browser.

The web console enables to perform these tasks:

  • Monitoring basic system features, such as hardware information, time configuration, performance profiles, connection to the realm domain
  • Inspecting system log files
  • Managing network interfaces and configuring firewall
  • Handling docker images
  • Managing virtual machines
  • Managing user accounts
  • Monitoring and configuring system services
  • Creating diagnostic reports
  • Setting kernel dump configuration
  • Managing packages
  • Configuring SELinux
  • Updating software
  • Managing system subscriptions
  • Accessing the terminal

For more information on installing and using the RHEL 8 web console, see Managing systems using the RHEL 8 web console.

3.2. Restarting the system using the web console

This procedure uses the web console to restart a RHEL system that the web console is attached to.

Prerequisites

Procedure

  1. Log into the RHEL 8 web console.

    For details, see Logging in to the web console.

  2. Click Overview.
  3. Click the Restart restart button.

    cockpit system restart pf4

  4. If any users are logged into the system, write a reason for the restart in the Restart dialog box.
  5. Optional: In the Delay drop down list, select a time interval.

    cockpit restart delay pf4

  6. Click Restart.

3.3. Shutting down the system using the web console

This procedure uses the web console to shut down a RHEL system that the web console is attached to.

Prerequisites

Procedure

  1. Log into the RHEL 8 web console.

    For details, see Logging in to the web console.

  2. Click Overview.
  3. In the Restart drop down list, select Shut Down.

    cockpit system shutdown pf4

  4. If any users are logged in to the system, write a reason for the shutdown in the Shut Down dialog box.
  5. Optional: In the Delay drop down list, select a time interval.
  6. Click Shut Down.

3.4. Configuring the host name in the web console

You can use the web console to configure different forms of the host name on the system that the web console is attached to.

3.4.1. Host name

The host name identifies the system. By default, the host name is set to localhost, but you can change it.

A host name consists of two parts:

Host name
It is a unique name which identifies a system.
Domain
Add the domain as a suffix behind the host name when using a system in a network and when using names instead of just IP addresses.

A host name with an attached domain name is called a fully qualified domain name (FQDN). For example: mymachine.example.com.

Host names are stored in the /etc/hostname file.

3.4.2. Pretty host name in the web console

You can configure a pretty host name in the RHEL web console. The pretty host name is a host name with capital letters, spaces, and so on.

The pretty host name displays in the web console, but it does not have to correspond with the host name.

Example 3.1. Host name formats in the web console

Pretty host name
My Machine
Host name
mymachine
Real host name - fully qualified domain name (FQDN)
mymachine.idm.company.com

3.4.3. Setting the host name using the web console

This procedure sets the real host name or the pretty host name in the web console.

Prerequisites

Procedure

  1. Log into the RHEL 8 web console.

    For details, see Logging in to the web console.

  2. Click Overview.
  3. Click edit next to the current host name.

    cockpit hostname pf4

  4. In the Change Host Name dialog box, enter the host name in the Pretty Host Name field.
  5. The Real Host Name field attaches a domain name to the pretty name.

    You can change the real host name manually if it does not correspond with the pretty host name.

  6. Click Change.

    cockpit hostname change pf4

Verification steps

  1. Log out from the web console.
  2. Reopen the web console by entering an address with the new host name in the address bar of your browser.

    cockpit hostname change verify pf4

3.5. Joining a RHEL 8 system to an IdM domain using the web console

This procedure uses the web console to join the Red Hat Enterprise Linux 8 system to the Identity Management (IdM) domain.

Prerequisites

  • The IdM domain is running and reachable from the client you want to join.
  • You have the IdM domain administrator credentials.

Procedure

  1. Log into the RHEL web console.

    For details, see Logging in to the web console.

  2. Open the System tab.
  3. Click Join Domain.

    idm cockpit join domain

  4. In the Join a Domain dialog box, enter the host name of the IdM server in the Domain Address field.
  5. In the Authentication drop down list, select if you want to use a password or a one-time password for authentication.

    idm cockpit join psswd

  6. In the Domain Administrator Name field, enter the user name of the IdM administration account.
  7. In the password field, add the password or one-time password according to what you selected in the Authentication drop down list earlier.
  8. Click Join.

    idm cockpit join

Verification steps

  1. If the RHEL 8 web console did not display an error, the system has been joined to the IdM domain and you can see the domain name in the System screen.
  2. To verify that the user is a member of the domain, click the Terminal page and type the id command:

    $ id
    euid=548800004(example_user) gid=548800004(example_user) groups=548800004(example_user) context=unconfined_u:unconfined_r:unconfined_t:s0-s0:c0.c1023

3.6. Configuring time settings using the web console

This procedure sets a time zone and synchronizes the system time with a Network Time Protocol (NTP) server.

Prerequisites

Procedure

  1. Log in to the RHEL 8 web console.

    For details, see Logging in to the web console.

  2. Click the current system time in Overview.

    cockpit time settings pf4

  3. In the Change System Time dialog box, change the time zone if necessary.
  4. In the Set Time drop down menu, select one of the following:

    Manually
    Use this option if you need to set the time manually, without an NTP server.
    Automatically using NTP server
    This is a default option, which synchronizes time automatically with the preset NTP servers.
    Automatically using specific NTP servers
    Use this option only if you need to synchronize the system with a specific NTP server. Specify the DNS name or the IP address of the server.
  5. Click Change.

    cockpit time change pf4

Verification steps

  • Check the system time displayed in the System tab.

3.7. Optimizing the system performance using the web console

In the web console, you can set a performance profile to optimize the performance of the system for a selected task.

3.7.1. Performance tuning options in the web console

Red Hat Enterprise Linux 8 provides several performance profiles that optimize the system for the following tasks:

  • Systems using the desktop
  • Throughput performance
  • Latency performance
  • Network performance
  • Low power consumption
  • Virtual machines

The tuned service optimizes system options to match the selected profile.

In the web console, you can set which performance profile your system uses.

Additional resources

3.7.2. Setting a performance profile in the web console

This procedure uses the web console to optimize the system performance for a selected task.

Prerequisites

Procedure

  1. Log into the RHEL 8 web console.

    For details, see Logging in to the web console.

  2. Click Overview.
  3. In the Performance Profile field, click the current performance profile.

    cockpit performance profile pf4

  4. In the Change Performance Profile dialog box, change the profile if necessary.
  5. Click Change Profile.

    cockpit performance profile change pf4

Verification steps

  • The Overview tab now shows the selected performance profile.

3.8. Disabling SMT to prevent CPU security issues using the web console

This section describes how to to disable Simultaneous Multi Threading (SMT) in case of attacks that misuse CPU SMT. Disabling SMT can mitigate security vulnerabilities, such as L1TF or MDS.

Important

Disabling SMT might lower the system performance.

Prerequisites

Procedure

  1. Log in to the RHEL 8 web console.

    For details, see Logging in to the web console.

  2. Click System.
  3. In the Hardware item, click the hardware information.

    cockpit smt hardware

  4. In the CPU Security item, click Mitigations.

    If this link is not present, it means that your system does not support SMT, and therefore is not vulnerable.

  5. In the CPU Security Toggles, switch on the Disable simultaneous multithreading (nosmt) option.

    cockpit smt disable

  6. Click on the Save and reboot button.

After the system restart, the CPU no longer uses SMT.

Additional resources

For more details on security attacks that you can prevent by disabling SMT, see: