By default, the installer automatically searches the $SYBASE directory for existing DA installations and uses the configuration values from the valid instance directory that has been most recently modified. You may install another instance into same directory for your upgrade or reinstallation.
To install another instance into the same $SYBASE directory, you must force the installer to use the new instance name, to stop it automatically choosing an existing one. If you choose a new instance name for an existing installation, the installation process is similar to an upgrade which reuses the existing configuration values.
Specify the agent or server instance name, issue these commands:
setup.exe/bin -i console -DDA_SERVER_INSTANCE_NAME=myserver2