I'm trying to follow intructions found here (http://www.jeremymorgan.com/tutorials/raspberry-pi/how-to-raspberry-pi-file-server/) on how to set up a file server with the Raspberry pi, but cannot mount my drive. The error I get is cannot find /dev/sda1. When I look into /dev, I see that I have no folders /DEV/SDA. Why is that and how can I create them?
As mentioned in my comment, do not plug the device into the pi after boot. Plug it in before you power up or use a hub.