What is one feature provided by vSphere that helps prevent performance bottlenecks?

The feature that helps prevent performance bottlenecks in vSphere is Storage DRS (Distributed Resource Scheduler). Storage DRS automates the process of load balancing across virtual machine storage resources by intelligently placing virtual disks and managing existing workloads.

When Storage DRS is enabled, it continuously monitors the network storage utilization and I/O load at the datastore level. If it detects a performance imbalance or overutilization on a particular datastore, it can automatically initiate actions to either migrate virtual machines or redistribute their workloads to ensure even resource utilization across the datastores. This proactive management helps to mitigate any potential performance bottlenecks that could arise due to uneven distribution of storage I/O and capacity.

In contrast, other options might not provide the same level of automated resource management or proactive performance optimization. For instance, storage balancing within the same virtual machine may not address overall storage contention. Manual migrations rely on administrator intervention and can be time-consuming, while periodic shutdowns of idle virtual machines may not effectively address ongoing performance issues faced by active VMs. Thus, Storage DRS is specifically designed to enhance performance and efficiency through automation and intelligent management.