8.2. Performing System Assessment

Install preupgrade-assistant
The preupgrade-assistant is a tool that scans through the existing RHEL 6 system and finds out how fit and ready a system is, to be upgraded to RHEL 7.
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.
SELinux policy in RHEL 7
SELinux policies have changed between RHEL 6 and RHEL 7. For a working SELinux policy in RHEL 7, execute the following command:
```
# semodule -r sandbox
```
Uninstall Cluster and HA related packages
Important
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
```