On 17.04, even the workaround that Ewan posted in #5 above doesn't work for me. If I add DefaultLimitNOFILE=40000 to /etc/systemd/user.conf and log out and log in again, prlimit still shows this:
adam:~$ prlimit
RESOURCE DESCRIPTION SOFT HARD UNITS
...
NOFILE max number of open files 4096 4096 files
adam:~$
On 17.04, even the workaround that Ewan posted in #5 above doesn't work for me. If I add DefaultLimitNOF ILE=40000 to /etc/systemd/ user.conf and log out and log in again, prlimit still shows this:
adam:~$ prlimit
RESOURCE DESCRIPTION SOFT HARD UNITS
...
NOFILE max number of open files 4096 4096 files
adam:~$