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Installation Guide
14 VMware, Inc.
Figure 1-2. Switchover
A switchover gracefully closes vCenter Server running on the active server and restarts it on the passive server,
including the component or service that caused the failure. For example, if the Primary server is active and the
Secondary server is passive, the Primary server is demoted to a passive role and is hidden from the network
when the Secondary server is promoted to an active role and is made visible to the network. The mechanics of
switchovers are discussed in more detail later in this guide.
Performance Protection
Ensuring that vCenter Server is operational and providing service at an adequate level of performance to meet
user demands is important. The vCenter Server Heartbeat plug-in provides these monitoring and pre-emptive
repair capabilities.
vCenter Server Heartbeat proactively monitors system performance attributes and can notify the system
administrator in the event of a problem. Additionally, it can be configured to take pre-emptive action to
prevent an outage.
In addition to monitoring vCenter Server services, vCenter Server Heartbeat can monitor specific attributes to
ensure that they remain within normal operating ranges. Similar to application monitoring, various rules can
be configured to trigger specific corrective actions whenever these attributes fall outside of their respective
ranges.
vCenter Server Heartbeat provides the same level of flexibility to define and perform multiple corrective
actions in the event of problems on a service by service or even attribute by attribute basis.
Data Protection
You can configure vCenter Server Heartbeat to protect the application environment. All data files that users or
the vCenter Server requires in the application environment are made available should a failure occur. After
installation, vCenter Server Heartbeat configures itself to protect files, folders, and registry settings for
vCenter Server on the active server by mirroring them in real time to the passive server. If a failover occurs, all
files protected on the failed server are available to users after the failover, hosted on the Secondary server.
vCenter Server Heartbeat intercepts all file system I/O operations on the active server. If the intercepted write
and update operations are within the protected set, these are placed in a queue on the active server referred to
as the active server’s send queue, pending transmission to the passive server. Each request is numbered to
maintain its order in the queue.
With the request in the active server’s send queue, vCenter Server Heartbeat allows the disk I/O to continue
with the requested disk operation.