# Total file descriptor limit sysctl fs.file-nr # User limit ulimit -Hn # Find out how many file descriptors are in use by user sudo lsof -u 2>/dev/null | wc -l # Increase file descriptor limit for a user echo "username hard nofile 64000" >> /etc/security/limits.conf echo "ulimit -n 64000" >> /home/username/.bashrc ; echo "ulimit -n 64000" >> /home/username/.bash_profile* # tested in centos