Chapter 5

VMware ESXi Overview

vSphere, vCenter, licensing, when enterprises choose it.

Learning objectives

Describe VMware ESXi architecture and how it differs from Proxmox
Navigate vSphere concepts: host, vCenter, datastore, vSwitch
Decide when Workshop Co. might encounter ESXi vs Proxmox in the wild

What is ESXi?

VMware ESXi is VMware's Type 1 hypervisor. It installs on bare metal with a minimal footprint (historically called a "vmkernel"). You manage VMs through:

Host Client — web UI on a single ESXi host (https://esxi-ip/ui)
vCenter Server — central management for many hosts, clusters, vMotion, HA

Workshop Co. uses Proxmox in their Edmonton basement, but their payment processor's MSP runs ESXi in a Calgary colocation facility. Knowing both ecosystems helps Marcus talk to vendors and migrate VMs if needed.

vSphere vocabulary mapped to Proxmox

VMware term	Proxmox equivalent
ESXi host	Proxmox node
vCenter	Proxmox datacenter / cluster UI
VM	QEMU/KVM VM
Datastore	Storage pool
Standard vSwitch / vDS	Linux bridge / SDN (optional)
vMotion	Live migration (both support with shared storage)
Snapshot	Snapshot

Worked example — MSP hosts Workshop Co. DR replica

Workshop Co. pays a Calgary MSP for off-site disaster recovery. The MSP runs ESXi 8:

DR environment (MSP side)

Host: esxi-calgary-03.corp.msp.ca
vCenter: Manages 12 hosts across AB/SK
Workshop Co. VM: workshop-db-replica — nightly replication from Proxmox
Datastore: vsan-prod-01 — VMware vSAN cluster

Marcus does not log into vCenter daily, but he needs to know:

Replica VM is powered off until failover test
Network port group VLAN-WorkshopCo isolates their traffic
Snapshot before MSP patching weekend — coordinated ticket

Licensing reality

ESXi free tier capabilities have changed over the years. Enterprise features (vCenter, HA, DRS) require paid licenses. Canadian SMBs often choose Proxmox for cost; enterprises with existing VMware investment stay on ESXi.

Creating a VM on ESXi (Host Client)

Virtual Machines → Create / Register VM
Select "Create a new virtual machine"
Name: workshop-web-dr, compatibility: ESXi 8.0
Guest OS: Linux, Debian 12 64-bit
Datastore: select SSD-backed store
Customize hardware: 2 vCPU, 4 GB RAM, VMXNET3 NIC, 32 GB thin disk
Mount Debian ISO, power on, install

# ESXi shell (if enabled) — list VMs
vim-cmd vmsvc/getallvms

# Power on VM by ID
vim-cmd vmsvc/power.on 42

VMXNET3 driver

ESXi's paravirtual NIC (VMXNET3) needs VMware tools or open-vm-tools inside the guest. Install after OS setup — same idea as Proxmox guest agent.

Try it yourself

Workshop Co.'s MSP proposes moving production from basement Proxmox to their ESXi cluster. List three questions Marcus should ask before agreeing.

Sample questions

Monthly cost vs current power + hardware amortization?
Where is data stored — Canada only? Who has admin access?
Migration plan: downtime window, rollback, DNS TTL for workshopco.ca?
Backup and snapshot policy — RPO/RTO in writing?

Check your understanding

What does vCenter add that a single ESXi Host Client cannot?
Is VMXNET3 a storage or network driver?

Answers

Multi-host management, clusters, HA, DRS, centralized permissions, and vMotion across hosts.
Network — VMware's paravirtual NIC.