The dbm service (database manager service) allow access to one or more relational databases. It will create and use DataSource objects. Such a DataSource object must be configured according to the database that will be used for the persistence of a bean.

The dbm service provides a generic driver-wrapper that emulates the XADataSource interface on a regular JDBC driver.It is important to note that this driver-wrapper does not ensure a real two-phase commit for distributed database transactions. When it is necessary to use a JDBC2-XA-compliant driver access to the databases must be done via a JDBC resource adapter XA compliant (more information can be found in Section 2.6, “Configuring JDBC Resource Adapters”

Here is the part of jonas.properties related to dbm service:

###################### JOnAS DBM Database service configuration
#
#  Set the name of the implementation class of the dbm service
jonas.service.dbm.class    org.ow2.jonas.dbm.internal.JOnASDataBaseManagerService

#  Set the jonas DataSources. This enables the JOnAS server to load
#  the data dources, to load related jdbc drivers, and to register the data
#  sources into JNDI.
#  This property is set with a coma-separated list of Datasource properties
#  file names (without the '.properties' suffix).
#  Ex: Oracle1,InstantDB1 (while the Datasources properties file names are
#                          Oracle1.properties and InstantDB1.properties)
jonas.service.dbm.datasources    HSQL1

For the dbm service it is possible to:

Access to a particular database via dbm service is configured in datasource.properties files that must be located in $JONAS_BASE/conf.