Create a Windows-XP VM using OpenNebula 3.6.0 in Ubuntu 12.04 with iSCSI datastore

Tasks in a nutshell:
1. To install OpenNebula 3.6.0 in Ubuntu 12.04 Server
2. To prepare a Ubuntu 12.04 machine as a iSCSI target
3. To prepare a Ubuntu 12.04 machine as OpenNebula Node and install
iSCSI initiator in it.
4. To create a iSCSI Datastore and save a WINXP qcow2 image in it.
5. To create a Windows-XP VM
6. To add an additional DATABLOCK image to iSCSI Datastore and attach the
same to running Windows XP VM
7. To add an additional DATABLOCK to Default shared storage and attach the
same to running Windows XP VM

OPENNEBULA 3.6.0 in UBUNTU 12.04 – WindowsXP -iscsi Datastore