How to increase Neo4j's maximum file open limit (ulimit) in Ubuntu?

Currently `ulimit -n` shows `10000`. I want to increase it to `40000`. I've edited "/etc/sysctl.conf" and put `fs.file-max=40000`. I've also edited `/etc/security/limits.conf` and updated hard and soft values. But still ulimit shows `10000`. After making all these changes I rebooted my laptop. I've access to root password. usr_name@usr_name-lap:/etc$ /sbin/sysctl fs.file-max fs.file-max = 500000 Added following lines in `/etc/security/limits.conf` - * soft nofile 40000 * hard nofile 40000 I also added following line in `/etc/pam.d/su`- session    required   pam_limits.so I've tried every possible way as given on other forums, but I can reach up to a maximum limit of `10000`, not beyond that. What can be the issue? I'm making this change because `neo4j` throws maximum open file limits reached error.