Which memory mechanism enables a virtual machine to request more memory on demand while running?

Which memory mechanism enables a virtual machine to request more memory on demand while running?

• A. Startup RAM
• B. Static Memory
• C. Virtual Memory
• D. Dynamic Memory

Answer: (D)

Dynamic memory management lets a hypervisor adjust the memory given to a VM while it’s running, so the virtual machine can request more RAM on demand without needing a restart. When the workload needs more memory, the guest can signal demand and the hypervisor allocates additional memory from the host’s pool up to a configured maximum. This often involves a ballooning mechanism inside the guest to indicate memory pressure, allowing the hypervisor to reclaim memory from other VMs if needed. When demand subsides, memory can be released back to the pool, keeping resources efficient. Startup RAM is fixed at boot, so it can’t adapt to changing workloads. Static memory implies no change during runtime. Virtual memory refers to the guest OS paging to disk, which is slower and not the host-level on-demand allocation described here. Dynamic memory perfectly matches the scenario of requesting more memory on demand while the VM continues running.

Dynamic memory management lets a hypervisor adjust the memory given to a VM while it’s running, so the virtual machine can request more RAM on demand without needing a restart. When the workload needs more memory, the guest can signal demand and the hypervisor allocates additional memory from the host’s pool up to a configured maximum. This often involves a ballooning mechanism inside the guest to indicate memory pressure, allowing the hypervisor to reclaim memory from other VMs if needed. When demand subsides, memory can be released back to the pool, keeping resources efficient.

Startup RAM is fixed at boot, so it can’t adapt to changing workloads. Static memory implies no change during runtime. Virtual memory refers to the guest OS paging to disk, which is slower and not the host-level on-demand allocation described here. Dynamic memory perfectly matches the scenario of requesting more memory on demand while the VM continues running.