virsh — Virtualization Shell for Managing VMs

virsh is a command-line interface for managing virtual machines via libvirt, typically used with KVM, QEMU, and other virtualization technologies. It supports operations like VM lifecycle management, storage, network, snapshots, and resource monitoring.

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Key Features

• Lifecycle Management: Start, stop, suspend, and destroy VMs.

• Persistent and Transient VMs: Manage both runtime and saved configurations.

• Storage and Networking: Control virtual disks, volumes, and virtual networks.

• Snapshots: Create and revert to VM snapshots.

• Remote Management: Manage VMs on remote hosts over SSH or TLS.

• Interactive and Non-interactive Use: Run commands or enter an interactive shell.

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Basic Syntax

virsh [options] <command> [args]

Example:

virsh start vm-name

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Common and Essential Subcommands

1. VM Lifecycle Management

• List VMs (running or all)

  virsh list          # Only running
  virsh list --all    # All domains (running + shut off)

• Start / Shutdown / Destroy / Reboot

  virsh start vm-name
  virsh shutdown vm-name
  virsh destroy vm-name        # Force off (like pulling power plug)
  virsh reboot vm-name

• Suspend / Resume

  virsh suspend vm-name
  virsh resume vm-name

• Autostart on Boot

  virsh autostart vm-name
  virsh autostart --disable vm-name

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2. Domain and Resource Info

• Get VM Information

  virsh dominfo vm-name
  virsh domuuid vm-name
  virsh domstate vm-name

• CPU and Memory Statistics

  virsh dommemstat vm-name
  virsh domstats vm-name

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3. VM Configuration and XML

• Dump or Edit XML Configuration

  virsh dumpxml vm-name         # Show XML
  virsh edit vm-name            # Edit XML with $EDITOR

• Define or Undefine Domains

  virsh define vm.xml           # Create from XML
  virsh undefine vm-name        # Remove config only

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4. Snapshot Management

• Create and Manage Snapshots

  virsh snapshot-create-as vm-name snap1 "Snapshot description"
  virsh snapshot-list vm-name
  virsh snapshot-revert vm-name --snapshotname snap1
  virsh snapshot-delete vm-name --snapshotname snap1

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5. Console and Access

• Connect to Serial Console

  virsh console vm-name

  To exit: Ctrl+]

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6. Storage Management

• List, Create, and Delete Volumes

  virsh vol-list default
  virsh vol-create-as default vol1.img 10G
  virsh vol-delete vol1.img --pool default

• Pool Management

  virsh pool-list
  virsh pool-start default
  virsh pool-refresh default

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7. Network Management

• List, Start, and Define Networks

  virsh net-list --all
  virsh net-start default
  virsh net-destroy default
  virsh net-define net.xml
  virsh net-autostart default

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8. Remote and Interactive Mode

• Connect to Remote Host

  virsh -c qemu+ssh://user@remote/system

• Enter Interactive Shell

  virsh

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Example Use Cases

Start a Virtual Machine

virsh start ubuntu-vm

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Check Running VMs

virsh list

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Create a Snapshot Before Upgrade

virsh snapshot-create-as ubuntu-vm pre-upgrade "Before system upgrade"

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Attach a CD-ROM ISO Image

virsh attach-disk ubuntu-vm /isos/ubuntu.iso hdc --type cdrom --mode readonly

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Conclusion

virsh is an indispensable tool for Linux-based virtualization environments using libvirt. It provides complete lifecycle control, resource introspection, and management capabilities for virtual machines, networks, and storage — both locally and remotely. It’s highly scriptable and favored for automation and infrastructure orchestration workflows.