Virtual Machines (OCR A-Level Computer Science): Flashcards
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12 cards from this deck
Virtual machine (VM)
Virtual machine (VM)
Software-based emulation of a physical computer
System virtual machines
System virtual machines
Emulate entire OS, run one OS inside another
Process virtual machines
Process virtual machines
Virtual environment for apps, e.g., JVM
Hypervisor
Hypervisor
VM manager that creates and manages VMs
Resources allocated by hypervisor
Resources allocated by hypervisor
CPU, memory, and storage resources
VM benefit: Resource optimisation
VM benefit: Resource optimisation
Multiple VMs share physical machine resources efficiently
VM benefit: Isolation
VM benefit: Isolation
Each VM operates independently, reducing risk
VM benefit: Cross-platform compatibility
VM benefit: Cross-platform compatibility
Run different OSs on single machine
VM drawback: Performance overhead
VM drawback: Performance overhead
Multiple VMs slow down host as resources are shared
Intermediate code
Intermediate code
Code not directly executed by OS, not hardware-specific
Java Virtual Machine (JVM)
Java Virtual Machine (JVM)
Runs Java bytecode, enables platform independence
Intermediate code benefit: Platform independence
Intermediate code benefit: Platform independence
Runs on any machine with relevant VM installed