Administration Guide › Features and Concepts › VM Single System Image for CA VM:Director

VM Single System Image for CA VM:Director

The VM Single System Image facility is a capability which enables multiple VM systems to be defined and managed as if they were a single VM system. CA VM:Director supports this facility by supplying the following environmental characteristics:

• The CP Object Directory on each member system is identical. A USER virtual machine definition is exactly the same, no matter which member system that user runs on.
• Directory Management Interfaces on each member system are identical. You enter product commands exactly the same way, no matter which member you run on. All authorizations to product commands and services are identical for an administrator, directory manager, or general user.

In a Single System Image complex, CA VM:Director operates as a set of servers, with one server virtual machine running on each member system. A master server runs on one member to perform all the function of a non-SSI product server, including:

• Processing commands
• Updating Configuration and Source Directory Entries
• Compiling the Object Directory

An agent server runs on each other member node to perform this subset of the functions of the master server:

• Compiling the Object Directory

The agent also implements additional new function:

• Responds to synchronization requests from the master product server
• Converts to replace the master server if an outage situation occurs