Or, How HA and FT works in VMware?
Or, What is HA (High Availability) in VMware?
Or, What is FT (Fault Tolerance) in VMware?
HA (High Availability) in VMware: VMware HA provides high availability on VMware Instances. In-case any of the ESXi host in a cluster will go down the Virtual Machines running on this particular ESXi host will be migrated to another available ESXi host.
But in case of any sudden hardware failure, which does not give enough time for VMs to be migrated to another available host, the VMs become unresponsive and in some cases it requires a reboot to be up and running...
FT (Fault Tolerance) in VMware: FT provides very efficient high availability of Virtual Machines by keeping one copy of virtual machine continuously replicated with all live contents changes. In-case one virtual machine will be down due to any reason like Host Sudden failures etc.. Another virtual machine running on some other available ESXi host in the same cluster will automatically come up in fractions of seconds (1 RTO approx.).
This feature is very useful when you are running very critical business application on Virtual environment e.g. Exchange Server.
