How to update RHEL in an airgapped environment

Created by Christopher Hall, Modified on Wed, 11 Dec, 2024 at 9:06 AM by Christopher Hall

https://access.redhat.com/solutions/45956

The --no-best flag must be given to yum/dnf to prevent it from ripping out docker in favor of podman. Read what the package manager is doing to ensure this does not happen.

If none of the methods mentioned in the above article work, you can update an offline system by using a online system to download the RPMs from and copy them over to the offline system.

1) On the online/connected system: Verify that the required packages are installed for downloading the RPMs:

Install yum-utils for Red Hat Enterprise Linux 7 , yum-plugin-downloadonly for Red Hat Enterprise Linux 6 or yum-downloadonly and yum-utils for Red Hat Enterprise Linux 5 on the machine which is connected to the Internet or any repository:

Note: The repository needs to be enabled on the online system for that system to be able to download the packages, you can verify this with the command # yum repolist

2) Copy the RPM db from the offline system to the online system (This could also be copied to a USB drive):

####### For RHEL 5, 6 and 7 systems  ########
# tar cjf rpm_db.tar.bz2 /var/lib/rpm
# scp rpm_db.tar.bz2 root@online:/tmp/

####### For RHEL 8 and 9 systems ########
# tar czhf rpm_db.tar.bz2 /var/lib/{rpm,dnf} /etc/{dnf*,os-release} 
# scp rpm_db.tar.bz2 root@online:/tmp/

3) Extract the database on the online system into an empty directory

# mkdir /tmp/rpm_db/
# tar xf /tmp/rpm_db.tar.bz2 -C /tmp/rpm_db/

4) On the online system download all the RPM packages and create a repository. We use --no-best here to avoid it fetching podman "upgrades"

# yum update --downloadonly --downloaddir /tmp/rpm_db --installroot=/tmp/rpm_db/ --no-best
# yum -y install createrepo
# createrepo /tmp/rpm_db

5) Copy the downloaded rpm updates from the online system to the offline system (This could also be copied to a USB drive)

# cd /tmp/rpm_db
# tar cjf /tmp/rpm-updates.tar.bz2 *.rpm repodata
# scp /tmp/rpm-updates.tar.bz2 root@offline:/tmp/
# ssh root@offline
# mkdir /tmp/rpms
# tar xf /tmp/rpm-updates.tar.bz2 -C /tmp/rpms

6) Update the offline system

Up to RHEL7 included:

# yum localinstall /tmp/rpms/*.rpm

RHEL8 and RHEL9:

# dnf --nogpgcheck --repofrompath OFFLINE,/tmp/rpms update