Security patches usually address vulnerabilities in third-party components and do not affect the

vCenter Server

functionality.

vCenter Server

bug fixes can introduce changes to the functionality without affecting the data format or database schema of the system.

Each update contains metadata with information about the updated content, for example, whether high-priority OS updates are included. The update metadata includes a list of components to be updated, the release date of the update, a list of fixed issues, time and disk space requirements, and information whether a reboot is required. The metadata can also contain a new

vCenter Server

version number, including a build number. In addition to the metadata, an update can contain optional components such as update scripts, new versions of

vCenter Server

software components, and new versions of OS components.

vCenter Server

can obtain software updates from either a URL or an ISO image. The URL can either point to the VMware Web repository or to a custom repository in which you upload the updates in ZIP format. To perform an update by using an ISO image, attach the image to the CD/DVD drive of the

vCenter Server

instance.

If you want to prevent issues related to the possibility of update installation failures, you should create a backup or take a snapshot of your

vCenter Server

instance before you start the update process. A backup can also be useful when an update is successfully installed. For example, you might decide to revert to the previous version if you encounter any undesired system behavior related to functional changes in the new software version.

You can run software update operations by using the

vSphere Automation

SDK or sending an HTTP request.

You can use interfaces from the

com.vmware.appliance.update

package to perform the operations. For more information, see the

Java API Reference

documentation.