Installing Hadoop In Ubantu Server

Hi,
I am having issue in configuring hadoop in the ubantu server. these are the following things i have done

1) Installed Ubantu server 12.04 on my vmware
2) installed Haddop 2.4.1
3) Installed Java 7 and followed the steps as per the document
4) when I tried starting starta-all.sh (it says command not found) I tried running start-yarn.ssh also
Any one encountered the same issue of having some solution for this, please let me know

Thanks
Vish