The document discusses using open source virtualization tools like Xen and libvirt to manage virtual machines from the command line, GUI, and programmatically using Python. It provides several examples of using tools like xm, virsh, and libvirt to explore the hypervisor's capabilities, start and stop VMs, and migrate a VM between hosts. It presents 11 virtualization "hacks" or techniques in the areas of exploration, basic tasks, and advanced tasks.

20. Hack #5 – Query the Hypervisor's Capabilities (cont'd) #!/usr/bin/python import libvirt conn = libvirt.open(None) print conn.getCapabilities() info = conn.getInfo() print "CPU model: %s" % info[0] print "memory: %d kB" % info[1] print "# of CPUs: %d" % info[2] print "CPU freq: %d MHz" % info[3] print "# of NUMA cell: %d" % info[4] print "# of CPU sockets: %d" % info[5] print "# of cores per socket: %d" % info[6] print "# of threads per core: %d" % info[7]

24. Hack #7 – Migrate a VM (cont'd) #!/usr/bin/python import sys, getpass, libvirt vmname = sys.argv[1] uri = sys.argv[2] mydata = "" def getCredentials(credentials, data): for credential in credentials: print credential[1] + ":", if credential[0] == libvirt.VIR_CRED_AUTHNAME: data = sys.stdin.readline() data = data[0:len(data)-1] credential[4] = data elif credential[0] == libvirt.VIR_CRED_PASSPHRASE: credential[4] = getpass("") else: return -1 return 0 flags = [libvirt.VIR_CRED_AUTHNAME,libvirt.VIR_CRED_PASSPHRASE] auth = [flags,getCredentials,mydata] localconn = libvirt.open(None) dom = localconn.lookupByName(vmname) remoteconn = libvirt.openAuth(None,auth,0) dom.migrate(remoteconn,libvirt.VIR_MIGRATE_LIVE,None,uri,0)