Virtual Machines

xCAT supports the following virtualization infrastructures:

Kernel-based Virtual Machine (KVM):

A full virtualization solution for Enterprise Linux distributions, known as the de facto open source virtualization mechanism and currently used by many software companies.

IBM PowerKVM:

A product that leverages the Power resilience and performance with the openness of KVM, which provides several advantages:

• Higher workload consolidation with processors overcommitment and memory sharing

• Dynamic addition and removal of virtual devices

• Microthreading scheduling granularity

• Integration with IBM PowerVC and OpenStack

• Simplified management using open source software

• Avoids vendor lock-in

• Uses POWER8 hardware features, such as SMT8 and microthreading

The xCAT based KVM solution offers users the ability to:

• provision the hypervisor on bare metal nodes

• provision virtual machines with the any OS supported in xCAT

• migrate virtual machines to different hosts

• install copy on write instances of virtual machines

• clone virtual machines

This section introduces the steps of management node preparation, hypervisor setup and virtual machine management, and presents some typical problems and solutions on xCAT kvm support.

• Set Up the Management Node for KVM
  • Install the kvm related packages
  • Set Up the kvm storage directory on the management node(optional)
• Install and Configure Hypervisor
  • Provision Hypervisor
  • Create network bridge on hypervisor
  • Start libvirtd service
• Manage Virtual Machine (VM)
  • Create Virtual Machine
  • Remove the virtual machine
  • Clone the virtual machine
  • Migrate Virtual Machines
• Trouble Shooting
  • VNC client complains the credentials are not valid
  • rpower fails with “Error: internal error Process exited while reading console log qemu: Permission denied”
  • rpower fails with “Error: internal error: process exited while connecting to monitor qemu: Permission denied”
  • rmigrate fails with “Error: libvirt error code: 38, message: unable to connect to server at ‘c910f05c35:49152’: No route to host.”
  • rmigrate fails with “Error: 38, message: failed to create directory ‘<dir-name>’: File exists: Unknown issue libvirt error code.”
  • Error: Cannot communicate via libvirt to kvmhost1
  • Fail to ping the installed VM