The correct fill-in answer is Ironic . Huawei’s official HUAWEI CLOUD Stack documentation clearly states that Ironic provides BMS management services by working with components such as Nova and Neutron . Huawei’s BMS usage guide also explicitly refers to BMS lifecycle management operations , including actions such as starting, stopping, forcibly stopping, and other lifecycle tasks. This confirms that Ironic is the component responsible for managing physical servers through their lifecycle in a Huawei Cloud Stack environment.

This is consistent with standard OpenStack architecture as well, where Ironic is the OpenStack Bare Metal service used to provision and manage physical machines similarly to how Nova manages virtual machines. In Huawei Cloud Stack, BMS is not handled as a simple ECS variant; instead, it relies on Ironic for provisioning, state transitions, and lifecycle orchestration of dedicated hardware resources.

Therefore, after correcting the sentence, the blank should be filled with Ironic , and the fully verified answer is Ironic .

The correct answer is B. L3 Agent . Official OpenStack Neutron documentation states that routers provide virtual Layer 3 services such as routing and NAT , and that the Networking service uses a layer-3 agent to manage routers. OpenStack also explicitly says that the neutron-l3-agent uses the Linux IP stack and iptables to perform L3 forwarding and NAT . This directly matches the wording of the question.

The other options do not fit. The L2 agent handles local virtual switch configuration and Layer 2 networking behavior, not routing and NAT. The DHCP agent provides DHCP services to tenant networks. “ NAT Agent ” is not the standard Neutron component name used in official OpenStack architecture. OpenStack documentation consistently identifies the L3 agent as the component responsible for router namespace management, forwarding, floating IP behavior, and source NAT functions.

This is also consistent with Huawei Cloud Stack networking architecture topics, where routing and NAT functions are tied to Neutron Layer 3 services. Therefore, the fully verified answer is B. L3 Agent .

The correct fill-in answer is PB level . Huawei’s official HUAWEI CLOUD Stack SFS documentation states that the maximum capacity of a single file is 240 TB , and it further explains that the file system capacity can be scaled to the PB level . This is the exact Huawei wording used to describe the upper expansion capability of SFS.

This reflects the design goal of SFS in Huawei Cloud Stack: to provide managed, shared file storage for applications that require large-scale file-system growth over time. In other words, the size of one individual file and the total expandable capacity of the file system are two different things. A single file has a stated upper limit, but the whole file system can continue to grow far beyond that limit, reaching petabyte-scale capacity

Therefore, after correcting the sentence structure, the blank should be filled with PB level , which is the official Huawei description of the scalable upper capacity for the file system.

========

The correct answer is B. BMS . For a typical web application architecture on HUAWEI CLOUD Stack, ECS provides the compute instances, IMS provides reusable images for quick deployment, AS enables elastic scale-out and scale-in based on demand, and ELB distributes traffic and improves availability. Huawei’s ECS and IMS documentation explicitly notes that ECS images can be used with Auto Scaling for dynamic expansion to meet peak demand, which directly supports quick deployment and elasticity.

BMS is a dedicated bare-metal service intended for scenarios needing direct physical hardware access, stronger isolation, or reduced virtualization overhead. It is useful for special workloads, but it is not required for the classic goals listed in the question, especially high cost-effectiveness and fast elastic web scaling. Those goals are more naturally achieved with ECS-based architectures plus ELB and AS. Huawei’s BMS positioning emphasizes physical-server management and performance advantages, not being a necessary part of a standard web application elasticity stack. Therefore, among the listed services, the one that is not required is BMS , making B the verified answer.

========

The statement is TRUE according to the official HOT specification. OpenStack Heat documentation shows the overall HOT structure and explains that heat_template_version identifies the YAML document as a HOT template of a specific version. This key is fundamental because it tells Heat which template format and feature set to validate.

The same HOT specification states that the resources section contains the declaration of the resources in the template and that this section with at least one resource should be defined in any HOT template , otherwise the template would not really do anything when instantiated. In other words, a valid HOT template intended to deploy a stack needs both the version declaration and a resource definition.

Other sections such as description, parameters, outputs, and conditions are documented as optional. That is why heat_template_version and resources stand out as the core required parts for normal HOT authoring. In Huawei Cloud Stack training contexts based on OpenStack Heat, these are treated as the mandatory structural elements of a HOT template. Therefore, the verified answer is A (TRUE) .

========

The statement is FALSE . Official OpenStack documentation clearly distinguishes pause from suspend . When a server is paused , OpenStack states that the state of the VM is stored in RAM , and the instance continues in a frozen state. This means memory is not written to disk during a pause operation. Because RAM is still occupied, a paused VM does not reduce resource usage to a minimal level in the way the question suggests.

By contrast, when a server is suspended , OpenStack documentation says that its state is stored on disk , all memory is written to disk , and the server is stopped. This is the action that is conceptually similar to hibernation. The distinction is important in OpenStack and Huawei Cloud Stack operations because pause is mainly used for temporary freezing of execution, while suspend is used when preserving state on disk is required. Therefore, the statement in the question incorrectly describes suspend , not pause . For that reason, the correct answer is B (FALSE) .

The statement is TRUE. Huawei Cloud Stack separates management responsibilities between operation administrators and VDC administrators. Huawei’s service-management documentation shows that operation administrators work at the platform-wide level and can publish cloud services and associate them with approval processes, which reflects their broader administrative scope. By contrast, VDC administrators work within the boundary of their own VDC and manage service usage and permissions inside that tenant-like scope. This architecture strongly supports the rule that both roles can participate in approval-process customization, but the visibility scope is different.

In practice, this means an approval process created by an operation administrator can be used as a global process across the platform, while a process created by a VDC administrator is limited to the VDC context rather than being exposed to all tenants or all service domains. This aligns with Huawei Cloud Stack’s layered governance model, where global service governance belongs to operation administrators and tenant-level governance belongs to VDC administrators. Therefore, the correct answer is A (TRUE).

========