  Recently, the number of detected galaxy counterparts of z > 2 Damped
Lyman-alpha Absorbers in QSO spectra has increased substantially so that we
today have a sample of 10 detections. M{\o}ller et al. in 2004 made the
prediction, based on a hint of a luminosity-metallicity relation for DLAs, that
HI size should increase with increasing metallicity. In this paper we
investigate the distribution of impact parameter and metallicity that would
result from the correlation between galaxy size and metallicity. We compare our
observations with simulated data sets given the relation of size and
metallicity. The observed sample presented here supports the metallicity-size
prediction: The present sample of DLA galaxies is consistent with the model
distribution. Our data also show a strong relation between impact parameter and
column density of HI. We furthermore compare the observations with several
numerical simulations and demonstrate that the observations support a scenario
where the relation between size and metallicity is driven by feedback
mechanisms controlling the star-formation efficiency and outflow of enriched
gas.
