Which setting prioritizes the disk access for virtual machines on a VMFS datastore?

The setting that prioritizes disk access for virtual machines on a VMFS datastore is disk shares. Disk shares determine the relative priority of virtual machine disk I/O during contention for datastore resources. In environments where multiple VMs are accessing the same datastore simultaneously, assigning disk shares allows administrators to control how the performance is allocated among those VMs. For example, a VM with high priority can be assigned more shares, enabling it to receive more disk resources compared to VMs with lower priority.

This mechanism is crucial in preventing resource starvation and ensuring that critical applications maintain performance even when multiple VMs compete for the same storage resources. It is particularly relevant in situations involving resource contention, where the demand for I/O exceeds the available capacity of the datastore.

In contrast, disk mode pertains to how a virtual disk is presented to a guest operating system and offers options like persistent or non-persistent modes, which do not impact the prioritization of storage access. Hard disk refers to the virtual hard drive itself without any implications for resource contention. Disk type typically refers to the format of the virtual disk, such as thick or thin provisioning, which affects storage efficiency but not the prioritization of access for I/O operations.