Hadoop on Amazon EC2 : Job tracker not starting properly
I'm not sure, whether this issue is related to Amazon EC2.I had this problem very often too - although I had a pseudo-distributed installation on my machine.
In these cases I could turn the safemode off manually and safely.
Try this command:bin/hadoop dfsadmin -safemode leave
I think you can't do wrong here. It seems to be a buggy feature of hadoop. I used 0.18.3, what version do you run?