It’s a single, purpose-built tool to upgrade in-place from RHEL 7.6 to RHEL 8 on Intel 64 architecture.
- The original subscription stays attached to the system
- Repo links are updated in the process
- Base OS + application streams + customs repos
- Easy to reuse the existing code base
- Easy to hook into the upgrade process
- 10 phases to hook into
- This tool doesn’t work with disk, LVM, or file-system encryption; UEFI is currently not supported
- It doesn’t work with multipath or any kind of network storage mount used as a system partition (for example, iSCSI, FCoE, or NFS)
- The whole system must be mounted under the root file system, with the exception of /home and /boot. For example, the /var or /usr directories cannot be mounted on a separate partition.
Source: Red Hat documentation.