Switchover happens when you manually switch access to a resource from one IBM® i system to another.
You usually initiate a manual switchover if you wanted to perform system maintenance, such as applying program temporary fixes (PTFs), installing a new release, or upgrading your system. Contrast this with a failover, which happens automatically when a outage occurs on the primary node.
When a switchover occurs, access is switched from the cluster node currently acting as the primary node in the recovery domain of the cluster resource group to the cluster node designated as the first backup. See recovery domain for information on how the switchover order is determined.
If you are doing an administrative switchover of multiple CRGs, the order you specify should consider the relationships between the CRGs. For example, if you have an application CRG that depends on data associated with a device CRG, the steps to an ordered switchover are:
- Quiesce the application on the old primary node (to quiesce changes to the data).
- Switch the device CRG to the new primary node.
- Switch the application CRG to the new primary node.