If your Exchange roles exist all on one server, then you only need to install the upgrade once. However, if your Exchange roles are broken across multiple servers, you will need to run the upgrade on each one individually and in a specific order to help prevent issues caused from upgrading. Install the upgrade in the order listed below which is based on the role types:
- Client Access Servers
- Hub and Edge Transport Servers
- Mailbox Servers
- Unified Messaging Servers
Once the service pack has been downloaded onto your Exchange server, extract the files somewhere easy to access and click the setup.exe file to start the upgrade process. On the menu click the link to install the service pack.
Once the upgrade starts, click the radio button to accept the license and then click next to start the readiness checks. The readiness checks verify the required prerequisites are met before running the upgrade.
This readiness check process can take five to ten minutes. If any of the prerequisites fail, those issues will have to be fixed before the upgrade can be installed. Warnings in yellow will not prevent you from proceeding with the install. Some common issues that will fail the prerequisites test:
Impending reboots from previous updates. If updates ran in the background and a reboot to finish them did not happen, this will fail the readiness check. To fix this issue, reboot the Exchange server and restart the setup.exe process which will run the prerequisites test again.
Error contacting the Active Directory domain controller. If you experience this error it will likely fail more than one of the prerequisites. To fix this issue the primary or root domain controller needs to seize the schema master role. To do this, follow the steps listed below:
- On the domain controller, open a command prompt and type "ntdsutil" and press enter.
- At the ntdsutil: prompt, type "roles" and press enter.
- At the fsmo maintenance: prompt, type "connections" and press enter.
- At the server connections: prompt, type "connect to server Domain Controller" and press enter.
- Still at the server connections: prompt type "quit" and press enter.
- Back at the fsmo maintenance: prompt, type "seize schema master" and press enter.
- Type "quit" and press enter twice to close the command prompt window.
- Go back to the Exchange server and restart the upgrade process.
- Verify all Exchange services are running on all Exchange Servers.
- Open the Exchange Management Console and verify all information stores are mounted.
- Send a test email outside of your domain, and reply back to make sure send and receives functions are working properly.