Here's a complete set of commands that you should run once you've attached the EBS volume to your EC2 instance:
link: [url]http://serverfault.com/questions/114944/mounting-an-attached-ebs-volume-in-ec2[/url]
mkfs -t ext3 /dev/sdf # (NOTE - if you created your EBS volume from a snapshot of another volume and want to preserve its data, skip this step)
echo "/dev/sdf /testName ext3 noatime 0 0" >> /etc/fstab
mkdir /testName
mount /testName
df -h # (you should now see a new /testName file system mounted on the EBS volume)
link: [url]http://serverfault.com/questions/114944/mounting-an-attached-ebs-volume-in-ec2[/url]