Proxmox VE Core Concepts: VM, LXC, Storage & Network

Before clicking buttons at random, get these four concepts into your head: you'll be clearer on "should I use a VM or LXC, where should I put the disk, how do I connect the network." Like reading the skill descriptions before playing a game — otherwise you'll keep dying.

Concept 1: The Difference Between VMs and LXC

One-sentence decision: need full isolation or running Windows → VM; want to save resources and the service is Linux → LXC. Choosing wrong is like wearing flip-flops to go hiking — not impossible, but you'll suffer.

# Create a VM (example)
qm create 100 --name my-vm --memory 1024 --cores 2
 
# Create an LXC container (example)
pct create 200 local:vztmpl/debian-12-standard_12.2-1_amd64.tar.zst --hostname my-ct --memory 512

Concept 2: Your Storage Choice Determines How Far You Can Go

Choose storage wrong and you'll hit walls with HA and migration later. Common types:

• local: single-node directory storage, beginner-friendly
• local-lvm: local LVM, good for snapshots and clones
• NFS/CIFS: shared network storage, cross-node capable
• ZFS/Ceph: advanced solutions for replication and high availability

# Check current storage status
pvesm status
pvesm list local

For live migration or HA, disks generally need to be on shared storage — otherwise the VM can't be moved. Like trying to move house but the furniture is still locked in someone else's place.

Concept 3: The Network Model (vmbr0)

PVE uses bridged networking by default: vmbr0 bridges to a physical NIC, making VMs look like they're directly connected to the physical switch. Simply put: one virtual cable, everyone shares the outgoing NIC.

[Physical NIC] --> [vmbr0] --> [VM1] [VM2] [VM3]

# Check current network configuration
cat /etc/network/interfaces

Concept 4: Nodes and Clusters

• Single node: one machine handles everything, good for getting started and homelabs
• Cluster: multiple hosts managed together, supports migration and HA — like forming a party for a dungeon

[Node1] <--> [Node2] <--> [Node3]
   \\_______ shared config (pmxcfs) _______//

The key point in one sentence: unified management plane, schedulable resources, failure can be taken over. Understanding this concept first makes the advanced section much easier to follow.

Next Steps

Once you've absorbed the core concepts, head into the high-frequency operations: backup, clone, migrate, snapshot. 👉 Common Patterns