1V0-21.20 · Question #105
Which vSphere component provides continuous availability for mission-critical virtual machines so users experience no loss of data and no interruption in service during a host failure?
The correct answer is A. vSphere Fault Tolerance. https://docs.vmware.com/en/VMware-vSphere/7.0/com.vmware.vsphere.avail.doc/GUID- 623812E6-D253-4FBC-B3E1-6FBFDF82ED21.html
Question
Which vSphere component provides continuous availability for mission-critical virtual machines so users experience no loss of data and no interruption in service during a host failure?
Options
- AvSphere Fault Tolerance
- BvSphere Replication
- CvSphere HA
- DvSphere vmotion
How the community answered
(45 responses)- A91% (41)
- B2% (1)
- C4% (2)
- D2% (1)
Explanation
https://docs.vmware.com/en/VMware-vSphere/7.0/com.vmware.vsphere.avail.doc/GUID- 623812E6-D253-4FBC-B3E1-6FBFDF82ED21.html
Topics
Community Discussion
6
Dervla O.Oct 18, 2025A is the right call here. Fault Tolerance creates a live shadow VM that runs in lockstep with the primary, so if the host dies the secondary takes over instantly with zero downtime and zero data loss. That lockstep mirroring is the key phrase the stem is testing, and it rules out the other three. HA restarts VMs after a failure, which means there IS an interruption. vMotion moves a running VM but requires the source host to stay alive. Replication is a DR tool with a recovery point objective, meaning you accept some data loss by design. When the stem says "no loss of data AND no interruption," that combination points exclusively to FT every time.
Luis F.Oct 20, 2025Solid breakdown, just worth adding that FT does cut your VM to a single vCPU in older vSphere versions so it is not always a drop-in for compute-heavy workloads even when zero downtime is the requirement.
Samuel O.Oct 8, 2025FT keeps a live shadow VM in lockstep, so zero RPO/RTO, right, unlike HA which still has a brief restart?
Dervla O.Oct 8, 2025FT gives you near-zero RTO because the secondary picks up mid-instruction, but RPO and RTO are not the same thing, and neither is truly zero when you account for network latency between the primary and shadow plus the checkpoint buffer window.
Luis F.Oct 31, 2025Honestly I keep coming back to C, vSphere HA, because it is literally the feature VMware built specifically to restart VMs automatically when a host goes down, so users get their services back fast with minimal downtime. Yeah you lose a few seconds on the failover but in practice that is what "continuous availability" means in most production environments I have read about.
Samuel O.Oct 31, 2025Luis, HA is a solid guess but the key word in the question is "continuous," and HA actually involves a restart that causes brief downtime, so the right pick is A, vSphere Fault Tolerance, which keeps a live shadow VM running in lockstep so there is literally zero interruption when a host fails.