The NFS (POSIX) access to the storage /pnfs is slow and we are still investigating the origin of the problem. We are already in contact with the developers.
For faster access please use the corresponding gfal commands (these need a valid proxy) [see wiki page https://t2bwiki.iihe.ac.be/GridStorageAccess]
The problems have been solved. The 'ls' command runs in a timely way.