6.2. Performing System Assessment

Install the preupgrade-assistant
The preupgrade-assistant is a tool that scans the existing Red Hat Enterprise Linux 6 system and checks whether it is ready to be upgraded.
Subscribe to the required repositories and install the preupgrade-assistant tool using the following commands:
```
# subscription-manager repos --enable rhel-6-server-extras-rpms --enable rhel-6-server-optional-rpms
# yum install preupgrade-assistant preupgrade-assistant-el6toel7
```
Run the preupgrade tool
Launch the preupgrade tool:
```
# preupg -v
```
Assess the results
1. View the following result of the preupgrade tool in a browser:
  /root/preupgrade/result.html
2. Make a note of all the components that are marked as Failed and Needs Action.
3. Share the findings with the Red Hat executive assisting with the upgrade process.
Check the SELinux policy in Red Hat Enterprise Linux 7
SELinux policies have changed between Red Hat Enterprise Linux 6 and Red Hat Enterprise Linux 7. For a working SELinux policy in Red Hat Enterprise Linux 7, execute the following command:
```
# semodule -r sandbox
```
Uninstall Cluster and HA related packages
Migration is not possible with Cluster and HA related packages installed on the system.
Uninstall Cluster and HA related packages by executing the following command:
```
# yum remove modcluster ricci openais corosync
```