Too many open files - File descriptor limit exceeded

root@linuxfix:~/too_many_open_files$

Too many open files

File descriptor limit exceeded

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

Find file leaks

Identify problematic processes:

lsof -p PID

ls -la /proc/PID/fd/

netstat -an | wc -l

What is Too many open files?

The process has reached its limit for the number of file descriptors it can have open simultaneously.

Common scenarios: Applications with file leaks, insufficient limits, or high-connection services.

Common Causes

File descriptor leaks
Low ulimit settings
High connection volume
Poor resource management

Debugging Tips

cat /proc/sys/fs/file-nr

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

Prevention

Proper file closing
Monitor file usage
Set appropriate limits

Additional Resources

File Descriptor Limits

Managing Linux file limits

files limits resources performance