The table below describes the main differences between High Availability (HA) and Fault Tolerance (FT) in VMware. The key difference is that FT eliminates downtime whereas HA does not.
| High Availability |
Fault Tolerance |
- Monitors heartbeat information provided by the VMware Tools package
- Automatically restarts affected virtual machine on other servers with spare capacity in the event of a physical server failure
- Automatically restarts affected virtual machines on the same physical server in the event of operating system failure
|
- Maintains a second copy of a virtual machine on another host
- Provides continuous availability for applications when a physical server fails
- Automatically triggers failover during a hardware outage
- Supports up to 4 vCPUs and 64GB of memory
|