About HP Integrity Virtual Machines

Integrity Virtual Machines is a soft partitioning and virtualization technology that provides operating system isolation, with sub-CPU allocation granularity and shared I/O. Integrity VM can be installed on an Integrity server or hardware partition (nPartition) running HP-UX. The Integrity VM environment consists of two types of components:

The VM Host virtualizes physical processors, memory, and I/O devices, allowing you to allocate them as virtual resources to each virtual machine.

Virtual machines are abstractions of real, physical machines. The guest operating system runs on the virtual machine just as it would run on a physical Integrity server, with no special modification. Integrity VM provides a small guest software package that aids in local management of the guest's virtual machine.

Figure 1-1 Hardware Consolidation Using Integrity VM

Guests are fully loaded, operational systems, complete with operating system, applications, system management utilities, and networks, all running in the virtual machine environment that you set up for them. You boot and manage guests using the same storage media and procedures that you would if the guest operating system were running on its own dedicated physical hardware platform. Even the system administration privileges can be allocated to specific virtual machine administrators.

One way to benefit from Integrity VM is to run multiple virtual machines on the same physical machine. There is no set limit to the number of virtual machines that can be configured, but no more than 256 virtual machines can be booted simultaneously on a single VM Host. Each virtual machine is isolated from the others. The VM Host administrator allocates virtual resources to the guest. The guest accesses the number of CPUs that the VM Host administrator allocates to it. CPU use is governed by an entitlement system that you can adjust to maximize CPU use and improve performance. A symmetric multiprocessing system can run on the virtual machine if the VM Host system has sufficient physical CPUs for it. Figure 1-1 illustrates how an HP-UX system and a Windows system can be consolidated on a single Integrity server. The HP-UX boot disk is consolidated onto the same storage device as the VM Host boot disk and the Windows guest storage. The Windows guest also has access to removable media (CD/DVD) that can be redefined as necessary.

Because multiple virtual machines share the same physical resources, I/O devices can be allocated to multiple guests, maximizing use of the I/O devices and reducing the maintenance costs of the data center. By consolidating systems onto one platform, your data center requires less hardware and management resources.

Another use for virtual machines is to duplicate operating environments easily, maintaining isolation on each virtual machine while managing them from a single, central console. Integrity VM allows you to create and clone virtual machines with a simple command interface. You can modify existing guests and arrange networks that provide communication through the VM Host's network interface or the guest local network (localnet). Because all the guests share the same physical resources, you can be assured of identical configurations, including the hardware devices backing each guest's virtual devices. Testing upgraded software and system modifications is a simple matter of entering a few commands to create, monitor, and remove virtual machines.

Integrity VM can improve the availability and capacity of your data center. Virtual machines can be used to run isolated environments that support different applications on the same physical hardware. Application failures and system events on one virtual machine do not affect the other virtual machines. I/O devices allocated to multiple virtual machines allow more users per device, enabling the data center to support more users and applications on fewer expensive hardware platforms and devices.