VMware Certified Professional - Data Center Virtualization (VCP-DCV) Practice Exam

When experiencing significant imbalance between NUMA nodes, what should an administrator do to address the issue?

1. Install more CPUs in the physical server

2. Balance RAM modules across processor sockets

3. Upgrade to the latest version of ESXi

4. Increase the number of virtual machines running

The correct answer is: Balance RAM modules across processor sockets

Balancing RAM modules across processor sockets is a key approach when managing a significant imbalance between NUMA nodes. NUMA (Non-Uniform Memory Access) architecture allows processors to access their own local memory more quickly than memory owned by other processors. When RAM is unevenly distributed across NUMA nodes, one node might experience high memory access latency, which can lead to performance degradation for applications that are sensitive to memory access times. By ensuring that RAM modules are balanced, each NUMA node can access memory more efficiently, thus optimizing performance. This balance allows for improved utilization of the system's processing capability, reducing contention and latency issues related to memory access. In contrast, installing more CPUs or increasing the number of virtual machines does not address the underlying issue of memory imbalances and could potentially exacerbate the problem by further complicating resource distribution. Upgrading to the latest version of ESXi might provide performance improvements or new features, but it won't necessarily resolve memory imbalance issues unless it includes specific improvements to NUMA management. Therefore, balancing RAM across sockets directly targets the performance concerns related to NUMA nodes, making it the most effective solution in this scenario.