The most important part first: Do have a failback plan if the installation does not succeed.
- Do a backup of your vCenter DB before attempting to upgrade.
- Check the vCenter server SSL certificate, it needs to have the subject alternative name field in it.
- Note down all your permissions you have set or use the fling "Inventory Snapshot"
- Check compatibility with all installed plugins for 5.1
- With approximately 50 VMs you are on the limit of a supported embedded database, seeing that you want to add another host this could eventually cause problems
- Installation order can be crucial when you want to keep your permissions
- Do not use any non ASCII characters for passwords, usernames, hostname etc.
After the installation of SSO I would recommend that you open an elevated shell and do the following:
# cd cC:\Program Files\VMware\Infrastructure\SSOServer\utils
# ssocli manage-identity-sources -a list -u admin
If domain users have permission on your vCenter server all the domains should be listed as an output, if they are not do not continue the installation
# ssocli manage-identity-sources -a create -u admin
This let's you add an identity source, for ease of use the Web Client can also be installed before installing the Inventory Service and upgrade vCenter Server to add the domains. If you omit this step permission loss will happen.
SSO does not understand domain trusts. vCenter 4.x would allow a user that is defined in domain B and joined to a group in domain A to connect to vCenter server when the group does have the correct permissions. Both domains need to be defined in the SSO for that scenario to still work in vCenter server 5.1.
- Install the Inventory Service
- Upgrade vCenter server
- Install the Web Client
- Upgrade the vSphere client
- Upgrade Update Manager
All the new features are only available in the Web Client, as is the GUI for SSO configuration.
Hope this helps you to have a smooth upgrade without any issues.