mdb saves it state in a series of files stored in a directory.
The default directory is .mdb under the users home
directory on Linux and Apple OS X. On windows it is the directory
.mdb in the users Application Data directory . This is
\Documents and Settings\User\Application Data\.mdb
where User is the users name. The actual location of the users home is obtained from the registry and may be different on your system.
This default can be changed by a command line argument or by setting the environmental variable MmsMdbRoot to the desired directory. Command line setting takes precedence. The specified directory can be either absolute or relative. In the latter case, it will be relative to the the users home or Application Data directory.