Chapter 2. Installing security updates
In RHEL, you can install a specific security advisory and all available security updates. You can also configure the system to download and install security updates automatically.
2.1. Installing all available security updates
To keep the security of your system up to date, you can install all currently available security updates using the yum utility.
Prerequisites
- A Red Hat subscription is attached to the host.
Procedure
Install security updates using
yumutility:# yum update --securityWithout the
--securityparameter,yum updateinstalls all updates, including bug fixes and enhancements.Confirm and start the installation by pressing y:
… Transaction Summary =========================================== Upgrade … Packages Total download size: … M Is this ok [y/d/N]: yOptional: List processes that require a manual restart of the system after installing the updated packages:
# yum needs-restarting 1107 : /usr/sbin/rsyslogd -n 1199 : -bashThe previous command lists only processes that require a restart, and not services. That is, you cannot restart processes listed using the
systemctlutility. For example, thebashprocess in the output is terminated when the user that owns this process logs out.
2.2. Installing a security update provided by a specific advisory
In certain situations, you might want to install only specific updates. For example, if a specific service can be updated without scheduling a downtime, you can install security updates for only this service, and install the remaining security updates later.
Prerequisites
- A Red Hat subscription is attached to the host.
You know the ID of the security advisory that you want to update.
For more information, see the Identifying the security advisory updates section.
Procedure
Install a specific advisory, for example:
# yum update --advisory=RHSA-2019:0997Alternatively, update to apply a specific advisory with a minimal version change by using the
yum upgrade-minimalcommand, for example:# yum upgrade-minimal --advisory=RHSA-2019:0997Confirm and start the installation by pressing
y:… Transaction Summary =========================================== Upgrade … Packages Total download size: … M Is this ok [y/d/N]: yOptional: List the processes that require a manual restart of the system after installing the updated packages:
# yum needs-restarting 1107 : /usr/sbin/rsyslogd -n 1199 : -bashThe previous command lists only processes that require a restart, and not services. This means that you cannot restart all processes listed by using the
systemctlutility. For example, thebashprocess in the output is terminated when the user that owns this process logs out.
2.3. Installing security updates automatically
You can configure your system so that it automatically downloads and installs all security updates.
Prerequisites
- A Red Hat subscription is attached to the host.
-
The
dnf-automaticpackage is installed.
Procedure
In the
/etc/dnf/automatic.conffile, in the[commands]section, make sure theupgrade_typeoption is set to eitherdefaultorsecurity:[commands] # What kind of upgrade to perform: # default = all available upgrades # security = only the security upgrades upgrade_type = security
Enable and start the
systemdtimer unit:# systemctl enable --now dnf-automatic-install.timer
Verification
Verify that the timer is enabled:
# systemctl status dnf-automatic-install.timer
Additional resources
-
dnf-automatic(8)man page on your system
