The hard limit of the number of open files is set to 1024 on my machine.
- I changed /etc/security/limits.conf and added 'idror hard nofile 65000'.
- In my shell I tried ulimit -n 65000. I get 'ulimit: value exceeds hard limit'
- In my shell I tried ulimit -Hn 65000. I get 'ulimit: can't raise hard limits'
So how can I increase the setting for the limit of open files without reboot?
You can just change it as root. For example: