Vmware and XenAPIs

Kevin Jacobson

Contents

• Overview– Xen– Vmware

• Comparison• APIs

– Xen API– Vmware API(s)

Xen

• Free, open source software• Hypervisor• Guests have independent “sandboxes”• Paravirtualization

– Software for hardware rather than direct access– Requires guests to be modified

http://uberhip.com/godber/plug/Xen_Primer/assets/xen_para.pngXen on Linux: A Young Hacker’s Illustrated PrimerAustin Gobder

Why Paravirtualization?

• Guests are portable• Only the Hypervisor needs to be ported• Better resource scaling • Windows licensing

VMware

• Commercial• Fully virtualized• Multiple flavors

– Server (ESX)– Workstation– Player– Fusion

…

• Solutions for servers and end-users

Full Virtualization

• Code runs directly on the CPU when possible• Host software checks for things which need

modification– Address space– Segmentation– Breakpoints– Some hardware calls

Comparison

VMware Xen

Open Source

Paravirtualization

Free

Multiple

Full Virtualization

Highly Supported by IT world

Xen API

• Python, C, Java, and Perl implementations• Abstraction above XML-RPC calls to the server

It’s So Simple!

Xen Summit 2007 Presentation by Ewan MellorPg. 6http://www.xen.org/files/xensummit_4/XenSummit_API_Slides_2007-04-18_Ewan.pdf

… it’s pretty confusing huh

• Let’s walk through an example use of the API• Power Cycling Example• Notice that classes in Xen’s API are more like

namespaces• All methods return references or metrics• Xen PyShell Example

VIX ( Deprecated Vmware API)

• VmPyware– Python Bindings for the Vix API– Much simpler than Xen API– Requires Windows Host OS

VmPyWare Examplefrom vix import Viximport time

vm = Vix()

print "Connecting"vm.Connect()

print "Opening vm"vm.Open("E:\\VMs\\Windows XP\\Windows XP Professional.vmx")

print "Powering On vm"vm.PowerOn()print "Waiting a bit..."time.sleep(10)print "Powering off vm"vm.PowerOff()

print "Reverting to snapshot 0"vm.GetRootSnapshot()vm.RevertToSnapshot()

print "Sleeping"time.sleep(10)

print "Disconnecting"vm.Disconnect()

VI (Virtual Infrastructure Management)

• Currently Supported API for VMWare• SOAP based

– WSDL– Cross-platform– Language agnostic

Basic Structure

Vmware Infrastructure SDK 2.5 Programmers Guide

Session Manager Object

• For logging into a system

Vmware Infrastructure SDK 2.5 Programmers Guide

The VM Object

…

Vmware Infrastructure SDK 2.5 Programmers Guide

Java Example

…

import java.net.URL;import com.vmware.vim25.*;import com.vmware.vim25.mo.*;import com.vmware.vim25.mo.util.*;

public class HelloVM {

public static void main(String[] args) throws Exception{

CommandLineParser clp = new CommandLineParser(new OptionSpec[]{}, args);String urlStr = clp.get_option("url");String username = clp.get_option("username");String password = clp.get_option("password");

ServiceInstance si = new ServiceInstance(new URL(urlStr), username, password, true);Folder rootFolder = si.getRootFolder();ManagedEntity[] mes = new

InventoryNavigator(rootFolder).searchManagedEntities("VirtualMachine");if(mes==null || mes.length ==0){

return;}VirtualMachine vm = (VirtualMachine) mes[0]; VirtualMachineConfigInfo vminfo = vm.getConfig();VirtualMachineCapability vmc = vm.getCapability();vm.getResourcePool();System.out.println("Hello " + vm.getName());System.out.println("GuestOS: " + vminfo.getGuestFullName());System.out.println("Multiple snapshot supported: " +

vmc.isMultipleSnapshotsSupported());si.getServerConnection().logout();

}}

//Example From VMware

Conclusion

Xen• Paravirtualization• XML-RPC Based API• Open Source

Vmware• Fully Virtualized• SOAP API• Commercial

ReferencesVMWare Infrastructure Programmer’s Guidehttp://www.vmware.com/support/developer/vc-sdk/visdk25pubs/

visdk25programmingguide.pdfVMWare Infrastructure Reference Guidehttp://www.vmware.com/support/developer/vc-sdk/visdk25pubs/ReferenceGuide/Xen API Docshttp://wiki.xensource.com/xenwiki/XenApiXen FAQhttp://wiki.xensource.com/xenwiki/XenFaq

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