I am facing issue of shutdown and related to the Question then I did as it is mentioned but at the ending I have got a message like
ureadahead will be reprofiled on next reboot
So I was afraid and checked and learned about it as askubuntu , Ubuntuforums, So I decided that it seems to be ok.
Now my only question or doubt is that message I have got. It will be re-profiled on next boot but how ? I am sure that I am not removing it but how it will be reprofiled and is it a good or bad way I wish to know.