I need to look this up every once in a while, and it’s not as easy to find as I like, so it lives here now.
To increase the open file limit for all users on pam-based Linux:
$ ulimit -n 1024 $ sudo bash $ echo '* - nofile 65535' >> /etc/security/limits.conf $ echo 'session required /lib/security/pam_limits.so' >> /etc/pam.d/login # logout. login. $ ulimit -n 65536