I am trying to make a transportable tablespace. The steps i do is
Make the tablespace readonly
Copy the datafiles using O/s command.

Now whenever i do this, it says the files are being shared. I am unable to copy the datafiles.
Could anybody tell me do i have to shutdown the database or take the database offline, before i copy the datafiles.
I am using noarchivelog mode.
Please reply at yumi_rama@yahoo.com
Thanks in advance,