The testfs ADIO implementation provides a harness for testing components
of ROMIO or discovering the underlying I/O access patterns of an
application. When testfs is specified as the file system type, no
actual files will be opened. Instead debugging information will be
displayed on the processes opening the file. Subsequent I/O operations
on this testfs file will provide additional debugging information.
The intention of the testfs implementation is that it serve as a
starting point for further instrumentation when debugging new features
or applications. As such it is expected that users will want to modify
the ADIO implementation in order to get the specific output they desire.