Setting Ulimit
I never found a solution to do it live (nothing worked that I found) so it looks like a relogin is required.
Check your maximum file limit
cat /proc/sys/fs/file-max
824460
This is different than your actual's user limit which you'll see below
ulimit -n
1024
Try and set it higher but it won't work
ulimit -n 65000
-bash: ulimit: open files: cannot modify limit: Operation not permitted
Set system wide defaults
sudo vi /etc/security/limits.conf
* hard nofiles 600000
* soft nofiles 500000
Making it live from a shell session (it won't work for your GNOME/XWindows session itself)
sudo su
root@homebox:/home/one# ulimit -n
1024
root@homebox:/home/one# ulimit -n 60000
ulimit -n
60000
root@homebox:/home/one# ulimit -n 60000
root@homebox:/home/one# ulimit -n
60000
root@homebox:/home/one# su - one
one@homebox:~$ ulimit -n
Tags:
ulimiti, relogin, maximum, proc, sys, fs, user, ll, ulimit, bash, modify, permitted, defaults, sudo, vi, etc, conf, nofiles, shell, gnome, xwindows, su, homebox,