Notes for Migration RHEL 7 to RHEL 8

Official Process of Migration from RHEL 7 to 8

Requirements:

Intel 64 Arch

Installation of Tool Leapp using Red Hat Subscription Manager)

wget https://access.redhat.com/sites/default/files/attachments/leapp-data3.tar.gz

At least 100MB of free space available on the boot partition

RHEL 7.6

Some important limitations

No rollback guarantied

Packages that are not a part of the Minimal (@minimal) or Base (@base) package groups might cause the upgrade process to fail.

No file system encryption supported on a system targeted.

No supported for Network Storage Mount (e.g. iSCSI, FCoE, or NFS)

Firewall will be disabled during the upgrade

The whole system must be mounted under the root file system, with the exception of /home and /boot.

  • Ex: /var, /opt, or /usr, etc… cannot be mounted on a separate partition

UEFI is currently unsupported.

 

Snapshot of all commands during the upgrade:

subscription-manager list --installed
subscription-manager repos --disable rhel-7-server-rpms --enable rhel-7-server-eus-rpms
subscription-manager repos --disable rhel-7-server-optional-rpms --enable rhel-7-server-eus-optional-rpms
yum versionlock clear
subscription-manager release --set 7.6
yum update; reboot;

subscription-manager repos --enable rhel-7-server-extras-rpms
yum install leapp
(begin the upgrade)
leapp preupgrade (optional)
leapp upgrade

cat /var/log/leapp/leapp-report.txt

(end of upgrade)
reboot
(After the upgrade): setenvforce 1; systemctl enable firewalld.service; systemctl start firewalld.service; cat /etc/redhat-release

Command leapp Tips:

  • leapp upgrade

use the extra parameters LEAPP_OVL_SIZE=2048MB for XFS system

where is the log of migration:

/var/log/leapp/leapp-report.txt