NFS mounts hang forever

That made a huge difference. With 32GB I saw a lot of swapping, which I don’t see anymore. It was particularly problematic that those ~60 GB of data are saved in nightly backups, which regularly ran until afternoon.

If you saw a lot of swapping with 32GB, then NFSv4 may have been hitting the concurrent session limits due to insufficient memory.

The server has 2 AMD EPYC 7252 8-Core processors.

Could be relevant as well. Another Rocky user complained of high memory usage on idle workloads, and apparently traced it to use of AMD EPYC. See Rocky Linux 8 6 GB memory in noncache used by kernel - #7 by fkaluza