Protect Against Host Failure

Downtime isn’t always planned, and a key part of ensuring high availability and business continuity is protecting against unplanned downtime as well. The two primary causes of unplanned downtime are host failure (when an ESXi host fails for some reason) and VM failure (when the guest operating system within a virtual machine fails for some reason). In this section, we’ll discuss how to protect against host failure; in the next section, you’ll learn how to guard against VM failure.

VMware vSphere provides two features that are intended to help you protect against the failure of an ESXi host:

• vSphere High Availability (HA) uses a heartbeat to detect the failure of an ESXi host and restarts virtual machines when it detects a host failure.