  We study the relaxational dynamics of flux lines in high-temperature
superconductors with random pinning using Langevin dynamics. At high
temperatures the dynamics is stationary and the fluctuation dissipation theorem
(FDT) holds. At low temperatures the system does not equilibrate with its
thermal bath: a simple multiplicative aging is found, the FDT is violated and
we found that an effective temperature characterizes the slow modes of the
system. The generic features of the evolution -- scaling laws -- are dictated
by the ones of the single elastic line in a random environment.
