login_bases = ['princeton', 'stanford', 'gt', 'uw', 'mpisws']
sites = Site.objects.filter(login_base__in=login_bases)
# collect nova nodes:
login_bases = ['princeton', 'stanford', 'gt', 'uw', 'mpisws']
sites = Site.objects.filter(login_base__in=login_bases)
# collect nova nodes: