If you're looking through Info Central, it probably won't take long to encounter a reference to Cassatt Active Response's discovery capability. This is the process by which Cassatt Active Response identifies and catalogs 1) a server's power controller and 2) the accompanying application server for use in the CAR environment.

Many systems provide some means of discovering resources and assets in their particular environment, but these frequently involve installing some kind of software agent across the environment to facilitate the discovery process. Cassatt Active Response, however, does not require any special agents. Rather, it only requires some configuration on the servers in the environment to enable already installed and available technologies (namely, DHCP and PXE). Once these are enabled, CAR discovery accounts for on-board power controllers and their accompanying application servers (including power controllers that service multiple servers in a blade enclosure.

One of the things that can be a little confusing is the difference between automatic and manual discovery:

• Automatic Discovery - With automatic discovery enabled, CAR discovers both the power controller (via its DHCP requests) and then the accompanying application node. This is a hands-off activity.
• Manual Discovery - With manual discovery (automatic discovery is disabled), you manually enter configuration data about the power controller (e.g., its IP address or MAC address) directly into the CAR controller. CAR then goes on to discover the accompanying application node.

So, except in rare circumstances, CAR discovers the application nodes whether you use automatic or manual discovery.

We probably tend to overload the term "discovery," so I'll try to follow this up with another entry or two and give more detail about how discovery works in Cassatt Active Response.

Labels: automatic discovery, manual discovery