Re: replication of whole database from one machine to another

amjad usman  wrote:
 
> now i want to copy the same data on the other machine for testing
> some queries.
> 
> can anybody tell me how i can do this?
 
You have many options.  You can review them in the documentation
here:
 
http://www.postgresql.org/docs/9.0/interactive/backup.html
 
> secondly, my PostgreSQL server sometimes does not start even if i
> have not changed any configuration file.
> whats the problem with this?
 
You haven't given enough detail to allow anyone to figure that out. 
Please read this page and post with more information:
 
http://wiki.postgresql.org/wiki/Guide_to_reporting_problems
 
-Kevin