Thank you very much for the suggestions.
Removed.
Yes, it is static and it is resolvable.
badin@fermi:~$ pbs_hostn -v fermi
primary name: fermi (from gethostbyname())
aliases: -none-
address length: 4 bytes
address: 192.168.0.100 (1677764800 dec) name: fermi
Firewall disabled, SELinux was never enabled.
Set.
Thanks now everything works I suspect, that the error was actually caused by PBS_CORE_LIMIT ā I misunderstood it as the number of CPU threads and not interpreted it as the maximum allowed size for core files, thank you very much. I think that this was also the mistake which lead to behaviour here https://community.openpbs.org/t/mom-config-incomplete/411