Proxmox VE from the command line: qm, pct, vzdump and pvesm

Goal

Perform the everyday read and lifecycle operations on a Proxmox VE node from the shell: listing and controlling VMs and containers, taking a backup, and checking storage status.

Prerequisites

Shell access to a Proxmox VE node as root (these tools act on the node with full rights; delegated, permission-checked access goes through the web UI or API instead); the node must already have the guest (VM or container) defined.

Steps

1. List KVM virtual machines: qm list shows VMID, name, status, memory and disk size for every VM on the node.
2. Start and stop a VM: qm start <vmid>; qm shutdown <vmid> sends an ACPI power-button event so the guest OS shuts down cleanly (depends on the guest handling it, as with libvirt's virsh shutdown; --timeout <seconds> bounds the wait and --forceStop 1 stops the VM if it has not finished by then); qm stop <vmid> ends the QEMU process immediately, like pulling the plug, which may damage guest data.
3. List LXC containers: pct list shows VMID, status and name for containers; VMs and containers share one ID space, unique across the whole cluster.
4. Start, stop and enter a container: pct start <ctid>, pct shutdown <ctid> (graceful) or pct stop <ctid> (immediate), and pct enter <ctid> for an interactive root shell inside the container from the host.
5. Take a backup of a guest (VM or container): vzdump <vmid> creates an archive using the defaults from /etc/vzdump.conf (mode snapshot unless configured otherwise); pass --storage <name> and --mode snapshot|suspend|stop explicitly in scripts. The vzdump manual documents these modes and their trade-off between guest downtime and consistency. Restore with qmrestore (VMs) or pct restore (containers) to test that the archive is usable.
6. Check configured storage: pvesm status lists every storage defined on the node, its type, total/used/available space and whether it is currently active — useful before starting a backup or provisioning a new disk to confirm there is room.
7. List the contents of one storage target (for example, to find a backup or ISO): pvesm list <storage>.

Expected result

qm list/pct list reflect the state change immediately after a start/stop command; vzdump prints a completion log naming the archive file and its storage location; pvesm status shows the storage's used percentage rising after a backup lands on it.

Limits and test basis

vzdump's stop mode shuts the guest down in an orderly way for the backup — for a VM only briefly, since the VM restarts while the backup runs, but a container stays stopped for the whole backup; snapshot mode has the least downtime at a small consistency risk. For VMs, snapshot mode is a live backup that copies data blocks while the VM runs; for containers it needs all backed-up volumes on storage that supports snapshots. VMID numbering is shared across VMs and containers, so qm and pct commands must be pointed at the correct ID and guest type.