Managing the VCS Configuration File: The hacf Utility

The hacf utility translates the VCS configuration language into a syntax that can be read by the VCS engine. Specifically, hacf translates the contents of the main configuration file, main.cf, into commands for the VCS server.

Verifying a Configuration

Use hacf to verify (check syntax of) the main.cf and the type definition file, types.cf. VCS does not execute if hacf detects errors in the configuration. No error message and a return value of zero indicates that the syntax is legal.

The variable config_directory refers to directories containing a main.cf file and any .cf files included in main.cf.

Loading a Configuration

The hacf utility verifies the configuration before loading it into VCS. The configuration is not loaded under the following conditions:

• If main.cf or include files are missing.
• If syntax errors appear in the .cf files.
• If the configuration file is marked "stale." A .stale file is created in the configuration directory when you indicate that you intend to change a running configuration. See Setting the Configuration to Read/Write for details.

Dumping a Running Configuration

A configuration is dumped (written to disk) when you indicate that you have finished changing it. The configuration is also dumped on a system when the system joins the VCS cluster. When VCS dumps a running configuration, it is always pretty-printed. VCS removes the .stale file following a successful dump. You can dump a configuration from the command line using the haconf -dump -makero command.

Multiple Versions of .cf Files

When hacf creates a .cf file, it does not overwrite existing .cf files. A copy of the file remains in the directory, and its name includes a suffix of the date and time it was created, such as main.cf.03Dec2001.175904. In addition, the previous version of any .cf file is saved with the suffix .previous; for example, main.cf.previous.