Virtual Machine Management

Proxmox VE provides powerful VM management capabilities with support for various operating systems and advanced features like snapshots, migration, and high availability.

Creating Virtual Machines

VM Creation Wizard

Node → Create VM
General Tab:
- VM ID: Unique identifier (100-999999)
- Name: Descriptive VM name
- Resource Pool: Optional organization
OS Tab:
- ISO Image: Select installation media
- Guest OS Type: Linux, Windows, or Other
System Tab:
- Machine: q35 (recommended)
- BIOS: OVMF (UEFI) or SeaBIOS
- SCSI Controller: VirtIO SCSI single
Hard Disk Tab:
- Storage: Select storage location
- Disk Size: Allocate appropriate space
- Format: qcow2 or raw
CPU Tab:
- Sockets/Cores: Configure CPU allocation
- Type: host or kvm64
Memory Tab:
- Memory: RAM allocation in MB
- Ballooning: Enable for dynamic allocation
Network Tab:
- Bridge: vmbr0 (default)
- Model: VirtIO (paravirt)

# Create VM with basic configuration
qm create 100 \
  --name "ubuntu-server" \
  --memory 2048 \
  --cores 2 \
  --net0 virtio,bridge=vmbr0 \
  --scsi0 local-lvm:32 \
  --ide2 local:iso/ubuntu-22.04.iso,media=cdrom \
  --boot order=ide2 \
  --ostype l26

# Start VM
qm start 100

VM Templates

Create reusable VM templates:

Templates save time and ensure consistent VM configurations across your infrastructure.

Install and configure base VM
Clean up (remove logs, SSH keys, etc.)
Shutdown VM
Convert to template: qm template 100
Clone from template: qm clone 100 101 --name new-vm

VM Configuration

Hardware Configuration

CPU Types:

host: Best performance, limited migration
kvm64: Good compatibility
Haswell/Broadwell: Specific CPU features

Advanced Options:

# Enable CPU hotplug
qm set 100 --hotplug cpu,memory,disk,network

# Set CPU limit (50% of host)
qm set 100 --cpulimit 0.5

# NUMA configuration
qm set 100 --numa 1

Memory Types:

Static: Fixed allocation
Ballooning: Dynamic allocation
Shares: Priority weighting

# Set memory with ballooning
qm set 100 --memory 4096 --balloon 2048

# Memory shares (higher = more priority)
qm set 100 --shares 1000

Disk Controllers:

VirtIO SCSI: Best performance
SATA: Good compatibility
IDE: Legacy support

# Add additional disk
qm set 100 --scsi1 local-lvm:50

# Enable SSD emulation
qm set 100 --scsi0 local-lvm:vm-100-disk-0,ssd=1

# Enable discard for thin provisioning
qm set 100 --scsi0 local-lvm:vm-100-disk-0,discard=on

Network Configuration

Standard Bridge

Advanced Options

# Configure network with VLAN
qm set 100 --net0 virtio,bridge=vmbr0,tag=100

# Enable multiqueue (cores/2, max 8)
qm set 100 --net0 virtio,bridge=vmbr0,queues=4

# Set bandwidth limit (10 Mbps)
qm set 100 --net0 virtio,bridge=vmbr0,rate=10

VM Operations

Basic Operations

# Start VM
qm start 100

# Shutdown VM (graceful)
qm shutdown 100

# Stop VM (force)
qm stop 100

# Reboot VM
qm reboot 100

# Suspend VM
qm suspend 100

# Resume VM
qm resume 100

Console Types:

noVNC: Web-based console
SPICE: Enhanced graphics protocol
Serial: Text-based console

# Access via command line
qm terminal 100

# VNC console
qm vncproxy 100

# Monitor console
qm monitor 100

Live Migration:

# Migrate to another node
qm migrate 100 proxmox-node2

# Migrate with specific options
qm migrate 100 proxmox-node2 --online --with-local-disks

Offline Migration:

# Migrate stopped VM
qm migrate 100 proxmox-node2 --with-local-disks

Snapshot Management

Snapshots capture VM state at a specific point in time, enabling quick rollbacks and testing scenarios.

# Create snapshot
qm snapshot 100 pre-update --description "Before system update"

# List snapshots
qm listsnapshot 100

# Rollback to snapshot
qm rollback 100 pre-update

# Delete snapshot
qm delsnapshot 100 pre-update

Backup and Restore

# Create backup
vzdump 100 --storage local-backup --mode snapshot --compress gzip

# Backup with specific options
vzdump 100 --storage nfs-backup --mode suspend --exclude-path /tmp --exclude-path /var/log

Via web interface:

Datacenter → Backup
Add backup job
Configure VMs, schedule, and retention

Via command line:

# Edit crontab
crontab -e

# Add backup job (daily at 2 AM)
0 2 * * * vzdump --all --storage local-backup --mode snapshot --quiet 1

# List available backups
ls /var/lib/vz/dump/

# Restore VM
qmrestore /var/lib/vz/dump/vzdump-qemu-100-2024_02_09-02_00_15.vma.gz 101

# Restore with different storage
qmrestore /var/lib/vz/dump/vzdump-qemu-100-2024_02_09-02_00_15.vma.gz 101 --storage local-lvm

Advanced VM Features

Cloud-Init Integration

Cloud-Init enables automated VM provisioning with custom configurations, SSH keys, and network settings.

# Add Cloud-Init drive
qm set 100 --ide2 local-lvm:cloudinit

# Configure Cloud-Init settings
qm set 100 --ciuser ubuntu --cipassword secure123 --sshkey ~/.ssh/id_rsa.pub --ipconfig0 ip=192.168.1.100/24,gw=192.168.1.1

# Resize disk after clone
qm resize 100 scsi0 +10G

GPU Passthrough

Prerequisites:

IOMMU enabled in BIOS
GPU in separate IOMMU group

# Enable IOMMU
echo 'GRUB_CMDLINE_LINUX_DEFAULT="quiet intel_iommu=on"' >> /etc/default/grub
update-grub

# Blacklist GPU driver
echo 'blacklist nouveau' >> /etc/modprobe.d/blacklist.conf

# Add GPU to VM
qm set 100 --hostpci0 01:00,pcie=1,x-vga=1

USB Passthrough

# List USB devices
lsusb

# Add USB device to VM
qm set 100 --usb0 host=1234:5678

# Add USB port
qm set 100 --usb1 host=1-2

Performance Optimization

CPU Optimization

CPU Pinning

NUMA Topology

CPU Governor

# CPU pinning (cores 2-3 to VM)
qm set 100 --cpus 2 --affinity 2,3

# NUMA configuration
qm set 100 --numa 1 --cpus 4 --memory 8192

Memory Optimization

# Disable memory ballooning for performance
qm set 100 --balloon 0

# Enable huge pages
echo 'vm.nr_hugepages = 1024' >> /etc/sysctl.conf
qm set 100 --hugepages 1024

Storage Optimization

# Use VirtIO SCSI with multiple queues
qm set 100 --scsi0 local-lvm:vm-100-disk-0,iothread=1,queues=4

# Enable write-back cache for performance
qm set 100 --scsi0 local-lvm:vm-100-disk-0,cache=writeback

# Disable cache for safety
qm set 100 --scsi0 local-lvm:vm-100-disk-0,cache=none

Troubleshooting

Common Issues

Always create snapshots before making significant changes to VMs.

VM Won't Start:

# Check VM configuration
qm config 100

# Check system resources
free -h
df -h

# Check logs
journalctl -u qemu-server@100

Performance Issues:

# Monitor VM performance
qm monitor 100
info cpus
info memory
info block

# Check host resources
top
iostat -x 1

Network Issues:

# Check bridge configuration
brctl show

# Test network connectivity
ping -c 4 gateway_ip

# Check firewall rules
iptables -L

Best Practices

Resource Planning: Don't over-allocate CPU and memory
Regular Backups: Implement automated backup strategies
Monitoring: Set up performance and resource monitoring
Security: Keep guest OS and Proxmox updated
Documentation: Maintain VM inventory and configurations
Testing: Test snapshots and backups regularly

Proper VM management ensures optimal performance, reliability, and maintainability of your virtualized infrastructure.

Virtual Machine Management

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