Whenever a process of a parallel task is spawned within the cluster, ParaStation MPI does not authenticate the user. Only the user and group ID is copied to the remote node and used for starting up processes.
Thus, it is not necessary for the user to be known by the
compute node, e.g. having an entry in
/etc/passwd. On the contrary, the
administrator may disallow logins for users by removing the
/etc/passwd. Usage of common
authentication schemes like
is not required and therefore limits user management to the
Authentication of users is restricted to login or frontend nodes and is outside of the scope of ParaStation MPI.