An example method to provide fault tolerance in a virtualized computing environment with a first host in a first fault domain and a second host in a second fault domain may include determining whether a primary virtualized computing instance and a secondary virtualized computing instance are both in the first fault domain. The secondary virtualized computing instance may be configured as a backup for the primary virtualized computing instance and supported by the first host. The method may further include: in response to determination that the primary virtualized computing instance and secondary virtualized computing instance are both in the first fault domain, selecting, from the second fault domain, the second host based on comparing a resource availability of each of a plurality of hosts that include the first host and the second host; and migrating the secondary virtualized computing instance from the first fault domain to the second fault domain.