One of the topics covered on the VMware vSphere: Install, Configure, Manage [V6.5] course is VMware Fault Tolerance.
vSphere Fault Tolerance is built on the ESXi host platform and comes as a function of the VMware vSphere HA cluster support. vSphere Fault Tolerance provides continuous availability by having an identical virtual machine run on separate ESXi hosts.
You can use vSphere Fault Tolerance for virtual machines that require protected against hardware failure.
vSphere Fault Tolerance provides continuous availability for such a virtual machine by creating and maintaining another virtual machine that is identical and continuously available to replace it in the event of a fail-over situation.
The fault tolerant virtual machine is called the primary virtual machine.
The duplicate virtual machine is called the secondary virtual machine.
It is created and runs on another ESXi host. The secondary virtual machine’s execution is identical to that of the primary virtual machine’s. The secondary virtual machine can take over at any point without interruption due to an ESXi host failure, providing fault-tolerant protection.
The primary virtual machine and the secondary virtual machine continuously monitor the status of each other to ensure that fault tolerance is maintained. A transparent fail-over occurs if the host running the primary virtual machine fails, in which case the secondary virtual machine is immediately activated to replace the primary virtual machine. A new secondary virtual machine is started, and fault tolerance redundancy is reestablished automatically.
If the host running the secondary virtual machine fails, it is also immediately replaced. In either case, users experience no interruption in service and no loss of data.
For a Hands on Experience of FT and more visit VMware Hands on Labs website and try:
HOL-1704-SDC-1 - vSphere 6 - Performance Optimization