GLYPH<SM590000> IT flexibility and responsiveness 

Virtualization enables clients to have a single, consolidated view of, and easy access to, all available resources in the network, regardless of location. It also enables clients to reduce the management of their environment by providing emulation for compatibility, improved interoperability, and transparent change windows. 

By adding any of these virtualization technologies to your environment, you create an on-demand, secure, and flexible infrastructure that is prepared to handle workload changes in your environment. IBM virtualization is the answer for the Cloud because it perfectly adheres to the hardware server and uses the LinuxONE functionalities with efficiency, high throughput, and security that is inherent of this platform. 

## 3.1.2 Hardware virtualization 

The following facilities are available in LinuxONE servers and are used to divide the hardware into LPARs. They are classified as type 1 hypervisors, are run directly on the hardware, and are known as “native” or “bare metal”: 

GLYPH<SM590000> IBM PR/SM™ is the facility on LinuxONE servers that provides another layer of virtualization. It is a hypervisor that is classified as type 1 and allows multiple LPARs to share physical resources, such as processors, memory, channel paths, and DASDs. 

GLYPH<SM590000> Dynamic Partition Manager (DPM) is a new administrative mode that was introduced to LinuxONE servers. A system can be configured in DPM mode or PR/SM mode. The mode is enabled before system power-on reset (POR). 

DPM provides the following advantages: 

–F a s t 

Much faster than managing with HCD and HCM (from hours to minutes). 

– Easy 

Intuitive user interface. No need for multiple administrators with different skills or tools. 

–P o w e r f u l 

The same efficient PR/SM hardware virtualization, without the complexity. It supports dynamic configuration changes with just a few mouse clicks. It provides a foundation for “bare metal” cloud. 

## 3.2 z/VM hypervisor and LinuxONE servers 

z/VM is the mature virtualization solution of IBM. It is reliable and flexible, and shares the resources to support thousand of guest servers with a high performance. As a hypervisor operating system, its security does not differ from the security of any other operating system on a server. However, the virtual infrastructure relies on the security of the hypervisor, so protecting the z/VM hypervisor often prevents attempts to breach the security of the operating system and compromises to the integrity of the operating system and data. 

The merger of z/VM and Linux on LinuxONE is perfect because z/VM can have hundreds of Linux servers that are running harmoniously while z/VM manages all of the resources of the LPAR with the benefit of improved price performance as workloads grow. 

