What should an administrator check to confirm high ballooning activity in a virtual machine?

To confirm high ballooning activity in a virtual machine, an administrator should focus on memory usage metrics. Ballooning is a memory reclamation technique used by hypervisors to manage memory resources efficiently across virtual machines. When the physical memory on the host is exhausted, the hypervisor uses a "balloon driver" installed on the guest OS to reclaim memory from the virtual machine.

Monitoring memory usage metrics allows the administrator to identify situations where the balloon driver has been activated, which indicates that the VM is experiencing memory pressure. High ballooning activity correlates with the VM consuming less physical memory due to the reclamation of memory by the balloon driver, which can lead to performance degradation.

In contrast, network usage statistics, physical host status, and resource allocation settings are not directly related to ballooning activity in the same way. While they may provide useful information about the overall environment or the configuration, they do not specifically indicate whether a VM is under memory pressure leading to ballooning. Therefore, tracking memory usage metrics provides the most relevant insight into ballooning activity within a virtual machine.