Complex SAN storage configuration

Some of the more powerful features of IBM® Power® Virtualization Center are featured in a more complex environment.

The following diagram shows an overview of a PowerVC environment that has multiple hosts, storage providers, and switches. The information under the graphic describes how and why the key components of the environment are configured. The detailed connections among the Virtual I/O Server and other resources are not depicted in this view. To view the detailed connections, see Figure 2.

This environment includes three hosts that are connected to the same HMC, two storage providers, and two SAN switches. It also includes two network switches, one for the data network and one for the management network. Both managed hosts include multiple Virtual I/O Servers: one has two and one has four. — Figure 1. High-level view of the environment

Following is a description of how and why the key components of the environment are configured:

Table 1. Components of a SAN storage configuration
Component	Description
Host	This environment includes three hosts: the PowerVC management server (Host 1) and two others (Hosts 2 and 3). Host 2 has four Virtual I/O Servers on it. Virtual I/O Servers 1 and 3 are redundant and so provide backup capability for each other. Virtual I/O Servers 2 and 4 are also redundant. Host 3 has two Virtual I/O Servers. Virtual I/O Servers 1 and 2 are redundant and so provide backup capability for each other.
Network	It is best practice to have separate management and data networks, each with their own switches to isolate and secure the traffic, so that is what is shown here. The Virtual I/O Server on the management server is connected to the Virtual I/O Server on the managed hosts using the management network. The management server is not connected to the data network. To do migration, Resource Monitoring and Control (RMC) must be set up. RMC requires that the deployed virtual machines also have a connection to the management network. That connection is not shown here. The figure above shows the network connections leading to the hosts. To see a detailed view of these connections on the host, see Figure 2.
Storage	This environment includes two storage providers and two SAN switches or fabrics. Both storage providers are connected to both switches. In addition, all of the Virtual I/O Servers are connected to both fabrics, so they have access to all storage. The figure above shows the storage connections leading to the hosts. To see a detailed view of these connections on the host, see Figure 2.
Virtual assets	Host 2 has a number of AIX® and Linux® virtual machines on it. Host 3 has a number of Linux virtual machines on it. These virtual machines are either pre-existing virtual machines that were brought into PowerVC, or they are the result of deploying a captured image. There are a number of captured images stored as image volumes on each of the storage providers. These images can be deployed across the hosts in the environment. In this example, all Virtual I/O Servers have access to all storage. However, it might be beneficial to dedicate storage resources to a particular purpose and therefore to dedicate certain Virtual I/O Servers to a particular set of storage resources. PowerVC provides a feature called storage connectivity groups, which enable you to group Virtual I/O Servers together logically to facilitate this kind of configuration. Storage connectivity groups also help you to ensure that a virtual machine that is migrating from one host to another will have access to the same storage resources on the destination host that it does on the source host. You create storage connectivity groups after you install PowerVC and register your hosts, storage, and networks. Note: When connecting multiple Virtual I/O Servers to the same SAN storage, follow the information in IBM PowerVM® best practices.

The following graphic shows a detailed view of the connections between the virtual machines on the hosts, the storage providers, and SAN and network switches:

This figure shows a close-up view of all of the network and storage connections between the two managed hosts from the previous figure as well as their Virtual I/O Servers and the virtual machines that reside on the hosts. — Figure 2. Detailed view of the connections on the host

Refer to Planning for hosts, Planning for networks, and Planning for storage and the rest of the planning information for guidance on how to make the decisions you need to make to plan your own environment.