Thanks for your support.
1) What do you mean by "ou can add different libraries individually and in parallel". Do I have to create a in_groups.csv and a in_libs.csv for each library and run CacheLibs.pl/CacheGroups.pl separately ?
2) "CacheGroups.pl also allows forking of library import to parallel jobs." : Is it with the "HOSTS" option ? I'm not sure how to use it (I work on a cluster)