Once the exchange servers are deployed, as part of day-2 operations, we need to perform lifecycle management of servers which includes the update management for exchange servers. Since the release of Exchange server 2013, Microsoft Exchange Server follows quarterly model for release of Cumulative Update (CU). Each CU release is as good as full installation of Exchange server that includes updates and changes from all previous CU’s. Therefore, while installing a new Exchange server, you should download and install the latest CU that includes both Exchange Server and the most current CU updates.
Always ensure that Exchange Servers have the supported CU version, so basically always update exchange servers with the latest CU, or a CU not older than the previous two versions. For example, if the latest Exchange Server CU is 14, then for your Exchange Servers to be supported, you must have at least CU12 installed.
For hybrid Exchange deployments, ensure that Exchange Servers have the supported CU version, so always update exchange servers with the latest CU, or a CU not older than the previous version. For example, if the latest Exchange Server CU is 14, then in order that your Exchange Servers in hybrid deployment are supported, you must have at least CU13 installed.
Cumulative Update deployment is different for Exchange Servers that are not members of Database Availability Group (DAG) than the Exchange Servers that are members of a Database Availability Group.
On a server that is not member of a DAG, the process of deploying cumulative update includes:
- Run the CU deployment
- Accept the License Agreement
- If the readiness check is completed, the installation procedure begins.
- After the CU installs successfully, you should restart the Exchange Server.
On a server that is member of a DAG:
- Before you run the CU setup, move all resources and active database copies to another DAG member to ensure that no user is connected to the server that is currently updating.
- Run the CU deployment
- Accept the License Agreement
- If the readiness check is completed, the installation procedure begins.
- Once the CU installation is completed and you reboot the server.
- Move the resources and active databases back to the updated server once server is online.
- Continue to install CU on the remaining DAG members.
Exchange Online update procedure
Microsoft takes care of updating Office 365 components with new features and capabilities so that customers can experience the improvements in the product. Microsoft deploys Office 365 updates to customers after thoroughly testing them.
Customers might choose to get Office 365 updates according to the Microsoft default release schedule or choose to receive them first. Administrators can choose the schedule of update deployments in their organisations by choosing one of the following options in the Office 365 admin centre:
- Standard release.
- Targeted release.
Standard release:
Standard release is the default option, in which organisations receive the latest updates as per the Microsoft default release schedule i.e. when all Office 365 customers receive them. We can choose this option if organisational strategy is to prepare the support staff for upcoming updates before deploying them.
Targeted release:
The Targeted release option enables organisations to get the latest updates first and provide early feedback to Microsoft. Administrators can choose to deploy updates only to selected individuals in an organisation (such as the IT team for early testing), or to deploy updates to the entire organisation.