# Choose component

You may choose what componets are you going to install on this screen and what installation type will be done.

Possible chooses are:

- Qmaster host - Main component in Grid Engine software. If you want to install Grid Engine you must install exactly one qmaster component per Grid Engine installation.

- Execution host(s) - Hosts that execute the tasks (jobs).

- Shadow host(s) - Shadow hosts provide a high availability feature to the cluster. In case that the qmaster fails (crash, network issue), one of the shadow hosts will take over the qmaster responsibility.

- Berkeley db host - Selecting it implies a Berkeley db host spooling option. The Grid Engine than spools data to a remote server. Not recommended as default option!

Installation types are as follows:

- Express installation – Targeted for the first time users of Grid Engine. Has significantely reduced set of configuration screens and simplified host selection panel.

- Custom installation – Prompts for all configuration parameters and includes more advanced host selection.