220-1201 Practice Question: That a virtual machine running on a workstation…

Answer analysis

Option-by-option breakdown

For each option: why learners choose it and why it is or isn't the right answer here.

• ✗

  The host does not have enough RAM for the VM

  Why it's wrong here

  A host with 16 GB of RAM allocating 8 GB to a single virtual machine typically provides ample memory for both the VM and the host operating system. This configuration leaves 8 GB for the host's processes and hypervisor overhead, which is generally sufficient to prevent memory contention or excessive swapping. Therefore, insufficient RAM is highly unlikely to be the primary cause of severe performance degradation for the VM in this specific scenario.

• ✓

  The VM has too many virtual CPUs assigned

  Why this is correct

  Assigning too many virtual CPUs (vCPUs) to a virtual machine, especially when the host's physical CPU cores are limited (e.g., a quad-core processor), can paradoxically degrade performance. The hypervisor must spend significant time and resources scheduling and context-switching these vCPUs across the available physical cores, leading to CPU scheduling overhead. This 'CPU ready time' means the VM's vCPUs are waiting for physical CPU resources to become available, resulting in severe slowness and reduced throughput for the virtual machine.

• ✗

  The SSD is too slow for virtualization

  Why it's wrong here

  Solid State Drives (SSDs) inherently offer significantly higher I/O operations per second (IOPS) and lower latency compared to traditional Hard Disk Drives (HDDs). For virtualization workloads, which are often I/O intensive, an SSD is typically a performance enhancement rather than a bottleneck. Therefore, it is highly improbable that an SSD would be 'too slow' for a virtual machine, especially when compared to other potential performance issues like CPU contention or memory starvation.

• ✗

  The VM is using a dynamic disk instead of a fixed-size disk

  Why it's wrong here

  A dynamic disk, which expands as data is written, can introduce a minor performance overhead compared to a fixed-size disk, which pre-allocates all its space. This overhead stems from the hypervisor needing to dynamically allocate and manage disk space as the VM writes data. However, this performance difference is generally negligible for typical workloads and would not be the primary cause of 'severe slowness' in a virtual machine, especially when other more impactful resource bottlenecks exist.

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