About known issues with GitHub Enterprise Server upgrades
GitHub is aware of the following issues that could impact upgrades to new releases of GitHub Enterprise Server. For more information, see "Known issues" in the GitHub Enterprise Server release notes.
GitHub strongly recommends regular backups of your instance's configuration and data. Before you proceed with any upgrade, back up your instance, then validate the backup in a staging environment. For more information, see Configuring backups on your instance and Setting up a staging instance.
Recommendations for server resources
If your appliance averages more than 70% CPU utilization, GitHub strongly recommends scaling up your server resources before upgrading to 3.11 or above. The new hardware or instance type should have more vCPUs to accommodate the additional load from new features and improvements included with the latest releases.