The possibility to change the number of virtual components, while the virtual machine is running, is limited by the kernel and operating system of the virtual machine itself. Guest kernel support for these features falls outside of the control of Oracle VM Manager, but the following guidelines are based on internal test data:
For guests that are running Oracle Linux, the ability to hot-add and hot-remove virtual CPUs is fully dependent on the kernel version that is installed on the guest. The minimum kernel version that has been shown to fully support the ability to hot-add and hot remove virtual CPUs is UEK2 QU5 v2.6.39-400.211.1. All supported versions of Oracle Linux are capable of hot-adding and hot-removing virtual disks. Support for hot-adding and hot-removing RAM on a guest running Oracle Linux is available with PVM (Oracle VM 3.4.1 and higher) and PVHVM (Oracle VM 3.4.2 and higher). It is also possible to hot-add virtual network interface cards.
All versions of Oracle Solaris running on a SPARC platform are capable of supporting the ability to hot-add and hot-remove virtual CPUs as required. Other components such as RAM and hard disks are also hot-swappable. It is also possible to hot-add virtual network interface cards.
It is important to note that when adding or removing memory for a running virtual machine on Oracle VM Server for SPARC, the request to add or remove memory may only be partially fulfilled. This is standard behaviour. For more information, see the Using Memory Dynamic Reconfiguration section in the Oracle VM Server for SPARC Administration Guide.
Access the Oracle VM Server for SPARC documentation at http://www.oracle.com/technetwork/documentation/vm-sparc-194287.html. To determine the version of the Oracle VM Server for SPARC documentation to reference, run the pkg list ldomsmanager command.
In such a case, Oracle VM Manager does not report any error after the memory add or remove operation, and indicates that the entire operation has succeeded. However the virtual machine may actually be allocated an amount of memory different from the amount indicated by Oracle VM Manager. The correct amount of memory is restored when the virtual machine is stopped and then restarted.
Guests running Oracle Solaris on an x86 platform do not have the same capabilities and the ability to hot-add and hot-remove virtual CPUs and RAM are not supported. However, as of Solaris 11, you are capable of hot-swapping hard disks. It is also possible to hot-add virtual network interface cards. Virtual machines running Oracle Solaris on an x86 platform are incapable of hot-removing a virtual CD-ROM device, due to the driver type used on this platform.
Guests running different versions of Microsoft Windows later than Microsoft Windows 2003 R2 SP2 are capable of supporting the option to hot-add virtual CPUs, however hot-removal of virtual CPUs is largely unsupported. It is possibly to detect the hot-removal of a virtual CPU on Microsoft Windows 10 if you scan for hardware changes in the Device Manager. No versions of Microsoft Windows support hot-swapping RAM. Hot-swappable virtual disks and the ability to hot-add virtual network interfaces are also supported, as long as the Oracle VM Paravirtual Drivers for Microsoft Windows are installed.