totem playing media file not present there
 

I am using ubuntu 8.04.
I played an mp3 in totem & meanwhile moved that file to another location.
Still I can move slider in totem to rewind or forward the song.
Only after the song has been played completely I get message 'location not found'.
Does that mean totem copies song into RAM so that it does not have to trouble hard disk for access during entire duration ?

Not necessarily.

More likely is that totem's "file handle" is still pointing at the file's first inode on disk, and it can find the rest from there.

When you move a file, it doesn't really move, but its directory entries are updated to reflect the "new" location. That's why mv is so much faster than cp ( try moving a big file, then try copying it somewhere else [both locations to be on the same partition please]).

Even of you moved the file to a different partition (which does mean the file really is moved [think about why it has to be]), totem would continue to play it as the old data is still where it was, until the filesystem decides to use that "empty" space and overwrite it.

very well said tredegar