1V0-2120 Associate Data Center Virtualization (VCTA-DCV 2024) Practice Questions

Reverting to a snapshot discards the current state of the virtual machine (including the file deletions) and restores it to the exact point-in-time when the snapshot was taken. This is the direct and intended method for this type of recovery. Cloning is a more complex process, and deleting the snapshot would remove the recovery point entirely. You cannot mount a snapshot like a separate disk.

CPU Ready time (%RDY) represents the percentage of time that a virtual machine was ready to run but could not get scheduled on a physical CPU because all CPUs were busy. While high CPU Usage is a factor, it's the Ready time that directly measures contention and indicates that VMs are being forced to wait for CPU resources. A consistently high Ready value (e.g., >5%) is a clear sign of a CPU bottleneck.

The publish/subscribe model is designed specifically for this use case. The administrator creates a 'Published' content library at the central site. Then, at each remote site, they create a 'Subscribed' content library that points to the published library. This setup automatically synchronizes the content from the publisher to all subscribers, ensuring consistent templates across the entire organization.

vSphere supports several block and file storage protocols. The primary supported protocols are iSCSI (block), Fibre Channel (block), Fibre Channel over Ethernet (FCoE, block), and NFS (file). SMB/CIFS is a common file sharing protocol but is not supported for creating vSphere datastores. FTP is a file transfer protocol and is not used for storage access.

EVC works by establishing a common CPU feature baseline for all hosts in a cluster. When a host with a newer CPU is added to an EVC-enabled cluster, it is checked for compatibility with the baseline. Since 'Cascade Lake' is a newer generation than 'Sandy Bridge', the new host is compatible. It will be successfully added to the cluster, and EVC will mask the advanced features of the 'Cascade Lake' processor that are not present in the 'Sandy Bridge' generation, ensuring vMotion compatibility across all hosts.

PCI Passthrough (DirectPath I/O) allows a physical PCI device, such as a NIC, to be exclusively assigned to a single virtual machine. This bypasses the hypervisor's virtualization layer for that device, providing the lowest possible latency and direct hardware access. This meets the strict requirements for the trading application. Creating a standard switch still involves the virtualization layer, a dedicated VMkernel port is for management traffic, and SR-IOV, while efficient, does not provide the same level of dedicated physical device mapping as Passthrough.

The VM Happiness score reflects how well a VM is getting the resources it is demanding. A score of 100% means it is getting everything it asks for. A score below 100%, such as 75%, indicates that the VM is experiencing some level of resource contention and is not receiving all of its requested resources (e.g., CPU ready time, memory swapping). It signifies moderate, not severe, contention and does not directly relate to vMotion success or snapshot health.

A host-to-VM affinity rule (a 'must run on' rule) dictates that a specific VM must run on a specific host or group of hosts. When trying to place a host into maintenance mode, DRS attempts to vMotion all VMs off of it. If a VM has a rule that binds it to that specific host, DRS cannot find a valid destination, and the task to enter maintenance mode will fail. Insufficient resources, HA admission control, or EVC mode are less likely to cause an outright failure if other hosts are available; they would typically generate specific warnings.

Virtual Volumes (VVOLs) is a storage architecture that allows storage arrays to become VM-aware, enabling operations to be offloaded and managed at a VMDK-granularity. Storage Policy-Based Management (SPBM) is the framework that works with VVOLs to apply storage policies (defining performance, availability, etc.) to individual VMs and their disks. Together, they meet the requirements for granular, policy-driven management and storage offloading. VMFS is a clustered file system, not a policy engine. Raw Device Mapping (RDM) is a legacy technology for direct LUN access. NFS is a file-based protocol, not typically used for this type of granular SAN integration.

This is true. When a snapshot is taken, the original base disk (.vmdk) is preserved in its current state and becomes read-only. A new delta disk file (e.g., VM-000001.vmdk) is created, and all subsequent writes from the guest OS are directed to this new delta disk. The parent disk remains untouched, allowing the VM to be reverted to that point-in-time.