By default Nuxeo comes with one repository, called "default". It's possible to configure another one (or more), which will be available at the top level of the Nuxeo tree of documents (it's named a "server" there).
To create a new repository called "other", you have to create custom copies of default-repository-config.xml and default-repository-ds.xml.
For documentation about content of those contributions, see RepositoryService and RepositoryManager.
Nuxeo 5.3.2 and above
The most recent versions of Nuxeo DM have their configuration based on templates (see Setup).
The recommended approach is to create your own set of templates which will be copied at runtime into config and/or datasources folder, depending on the packaging you're using. For the new datasource used by the other repository, do not hesitate to define new parameters and set them in your $NUXEO_CONF.
Nuxeo 5.3.1 and before with JBoss packaging
$JBOSS/server/default/deploy/nuxeo.ear/config/other-repository-config.xml, with content:
$JBOSS/server/default/deploy/nuxeo.ear/config/other-platform-config.xml, with content:
$JBOSS/server/default/deploy/nuxeo.ear/datasources/other-repository-ds.xml, with content:
In doubt, check the standard files default-repository-config.xml and default-repository-ds.xml from a working configuration for the proper file content. Pay particular attention to the content of the <rar-name> tag, which must match the file name actually deployed in your Nuxeo instance.
Nuxeo 5.3.1 and before with Tomcat packaging
$TOMCAT/nxserver/config/other-repository-config.xml, with content:
The repository config embeds the datasource configuration ; replace the default configuration above based on H2 database with your own settings.
$TOMCAT/nxserver/config/other-platform-config.xml, with content: