Final answer:
When remediating hosts in a cluster, disabling Fault Tolerance (FT) is essential because it requires active VMs on separate hosts, which isn't compatible with maintenance mode. High Availability (HA) and Distributed Resource Scheduler (DRS) may also be disabled to prevent VM restarts on other hosts and avoid VM migrations that interfere with the remediation process.
Step-by-step explanation:
When remediating hosts in a cluster, particularly in a vSphere environment, it's critical to consider high availability (HA), distributed resource scheduler (DRS), fault tolerance (FT), and enhanced vMotion compatibility (EVC). For remediating tasks which typically involve operations such as patching or upgrades that require hosts to be put into maintenance mode, fault tolerance (FT) should be temporarily disabled since it requires both the primary and secondary VMs to be running on separate hosts. High availability (HA) should also be considered as it may automatically restart VMs on other hosts when a host is put into maintenance mode, potentially leading to resource contention. The distributed resource scheduler (DRS) can also interfere with remediation by moving VMs around in an effort to balance the load, while enhanced vMotion compatibility (EVC) generally does not need to be disabled as it pertains to CPU compatibility during migrations but doesn't directly impact maintenance tasks.