VCA vSphere High Availability & Fault Tolerance 1 — Questions and Answers
Question 1: What does VMware vSphere High Availability (HA) protect against?
- Planned maintenance downtime for ESXi hosts
- Unplanned ESXi host failures by automatically restarting VMs on other cluster hosts (Correct answer)
- Storage array failures by replicating data in real time
- Network outages by rerouting traffic around failed uplinks
Correct answer: Unplanned ESXi host failures by automatically restarting VMs on other cluster hosts
vSphere HA monitors ESXi hosts in a cluster and automatically restarts virtual machines on surviving hosts when a host failure is detected.
Question 2: What is the role of the HA master host in a vSphere HA cluster?
- It runs all virtual machines in the cluster
- It monitors heartbeats from slave hosts and orchestrates VM restarts on failure (Correct answer)
- It manages vCenter Server licensing for the cluster
- It serves as the primary storage node for all datastores
Correct answer: It monitors heartbeats from slave hosts and orchestrates VM restarts on failure
The HA master host monitors all slave hosts via network and datastore heartbeats, and is responsible for restarting VMs when it detects that a slave host has failed.
Question 3: What is VMware Fault Tolerance (FT) and how does it differ from HA?
- FT restarts VMs after failure, while HA keeps a shadow VM running in lockstep
- FT keeps a shadow VM running in lockstep for zero-downtime failover, while HA restarts VMs (Correct answer)
- FT protects storage while HA protects compute resources
- FT requires shared storage while HA works with local storage
Correct answer: FT keeps a shadow VM running in lockstep for zero-downtime failover, while HA restarts VMs
FT maintains a live shadow VM that mirrors the primary VM in real time, providing zero-downtime failover, whereas HA simply restarts VMs after detecting a host failure.
Question 4: What is an HA admission control policy used for?
- Restricting which administrators can power on VMs in the cluster
- Ensuring the cluster retains enough capacity to restart VMs after a host failure (Correct answer)
- Controlling which datastores new VMs can be provisioned on
- Setting the order in which VMs restart after an HA event
Correct answer: Ensuring the cluster retains enough capacity to restart VMs after a host failure
HA admission control reserves cluster resources (CPU and memory) to guarantee that surviving hosts have sufficient capacity to restart all VMs from a failed host.
Question 5: What is the maximum number of vCPUs supported per VM when VMware Fault Tolerance (FT) is enabled?
- 1 vCPU
- 4 vCPUs
- 8 vCPUs (Correct answer)
- 16 vCPUs
Correct answer: 8 vCPUs
In vSphere 6.x and later, FT supports up to 8 vCPUs per protected virtual machine.
Question 6: What are datastore heartbeats used for in a vSphere HA cluster?
- Synchronizing snapshots across cluster hosts
- Distinguishing between a network partition and a host failure (Correct answer)
- Replicating VM disk files between datastores
- Verifying storage performance benchmarks
Correct answer: Distinguishing between a network partition and a host failure
Datastore heartbeats allow the HA master to determine whether an unresponsive host has actually failed or is simply isolated due to a network partition.
VCA vSphere High Availability & Fault Tolerance 1
What does VMware vSphere High Availability (HA) protect against?