Virtual machines (VMs) are the building blocks of modern IT infrastructure—encapsulated “computers” that run on software rather than physical hardware. Think of a VM as a fully functional PC, complete with its own CPU, memory, storage, and network interfaces, but packaged as files and managed by a hypervisor or cloud control plane. Below, we’ll unpack how VMs work in four leading platforms: VMware, Azure, AWS, and Oracle Cloud.
VMware Virtual Machine
At its core, a VMware VM is a guest operating system running atop the ESXi hypervisor on a physical host. Key characteristics:
- Isolation & Encapsulation: Each VM lives in its directory of configuration files (.vmx), virtual disks (.vmdk), and logs—fully sandboxed from its neighbours.
- Advanced Services: vMotion for live migration, Distributed Resource Scheduler (DRS) for automated load balancing, and snapshots for instant rollbacks give datacenter operators granular control.
- On-Premise Focus: Ideal for organisations with existing server investments, private clouds, or strict data-sovereignty requirements.
Azure Virtual Machine
Azure Virtual Machines bring that same VM concept into Microsoft’s public cloud:
- Pre-Built Images: Choose from hundreds of Windows and Linux images (including SQL Server, Ubuntu, CentOS) in the Azure Marketplace.
- Size & Scale: VM sizes range from tiny burstable instances for dev/test, all the way to GPU-accelerated, high-memory SKUs for AI and big data.
- Integrated Services: Plug directly into Azure Virtual Network, Azure Backup, and Azure Monitor, while paying per-second for compute and disk usage.
AWS Virtual Machine (EC2 Instance)
Amazon EC2 instances are VMs on AWS, defined by the underlying Amazon Machine Image (AMI) and instance type:
- AMI Foundation: Every VM boots from an AMI, which bundles your OS, application server, and custom settings. You can use AWS-provided AMIs or craft your own.
- Instance Types: From tiny t-series burst-capable instances to memory-optimised R-series and compute-optimised C-series, there’s a right fit for every workload.
- Elastic Architecture: Auto Scaling Groups let you automatically add or remove instances based on demand, ensuring performance and cost-efficiency.
Oracle Cloud Virtual Machine
Oracle Cloud Infrastructure (OCI) offers VMs as “compute instances” on shared or dedicated hosts:
- Flexible vs. Predefined Shapes: Pick a one-size-fits-many shape, or tailor your vCPU and RAM exactly to your needs, then resize on the fly.
- Enterprise-Grade Security: Built-in isolation, customer-controlled encryption keys, and SOC-compliant regions make OCI VMs a go-to for regulated industries.
- Seamless Integration: Connect your VMs with Oracle’s Autonomous Database, Load Balancer, and high-performance block storage through a low-latency virtual cloud network.
Choosing the Right VM
Whether modernising an on-prem datacenter with VMware, extending the footprint into Azure or AWS, or tapping into Oracle’s enterprise pedigree, virtual machines give:
- Rapid provisioning and teardown
- Fine-grained resource control
- Cost alignment with actual usage
- The foundation for containers, serverless functions, and other cloud-native patterns
In the next post, we’ll dive into VM networking patterns and best practices for security and performance tuning. Stay tuned!