EMFILE - Too many open files

root@linuxfix:~/emfile$

EMFILE

Too many open files

Solutions

Prerequisites: Start by updating your system to resolve common issues and ensure the solutions provided below are compatible with your current environment.

check_latest_version && sudo apt update && sudo apt upgrade -y

Check current limits

View file descriptor limits:

ulimit -n

cat /proc/sys/fs/file-max

lsof | wc -l

Increase limits

Raise file descriptor limits:

ulimit -n 4096

echo "* soft nofile 4096" >> /etc/security/limits.conf

echo "* hard nofile 8192" >> /etc/security/limits.conf

Find file leaks

Identify processes with many open files:

lsof -p process_id

ls -la /proc/process_id/fd/

netstat -an | grep ESTABLISHED | wc -l

What is EMFILE?

EMFILE occurs when a process has reached its limit for open file descriptors.

Common scenarios: Applications opening many files without closing them, file descriptor leaks, or insufficient file descriptor limits.

Common Causes

File descriptor leaks in applications
Too many files opened simultaneously
Low file descriptor limits
Network connections counting as files
Pipes and sockets not closed

Debugging Tips

cat /proc/sys/fs/file-nr

lsof | awk '{print $2}' | sort | uniq -c | sort -nr

ps aux | grep process_name

cat /proc/process_id/limits

Prevention

Always close opened files
Monitor file descriptor usage
Set appropriate limits
Fix resource leaks in applications

Additional Resources

Linux File Descriptor Limits

Managing file descriptor limits

errno files limits resources