To specify a non-default location for the log directory, set the logDevice=logDirectoryPath attribute on the database connection URL.
This attribute is meaningful when you are creating a database or when you are restoring a database using roll-forward recovery. You can specify logDevice=logDirectoryPath as either an absolute path or as a path that is relative to the directory where the JVM is executed.
Setting logDevice=logDirectoryPath on the database connection URL when you create the database adds an entry to the service.properties file. If you ever move the log manually, you will need to alter the entry in service.properties. If you move the log back to the default location, remove the logDevice entry from the service.properties file.
To check the log location for an existing database, you can retrieve the logDevice=logDirectoryPath attribute as a database property by using the following statement:
VALUES SYSCS_UTIL.SYSCS_GET_DATABASE_PROPERTY('logDevice')
For more information, see Roll-forward recovery in this manual and "logDevice=logDirectoryPath attribute" in the Derby Reference Manual.