Shell command execution times are slow inside container (ps, ls, scp etc.)

Expected behavior

I would expect a simple directory listing ls -la to take milliseconds. Likewise with secure copy etc.

Actual behavior

Running just about any command inside my container results in a painfully slow execution time.

Additional Information

Docker image used: FROM php:7.1-apache
Host OS: C4.xlarge AWS hosted running Ubuntu

Steps to reproduce the behavior

  1. docker exec -it container_name bash
  2. run any bash command

What would I like help with?

What diagnostic tools are available in order to get to the heart of the issue?