cluster tablespace, log file group

[ctx2002]

Hi guys:

I had created tablspaces and log file group for our cluster system.

are there any commands similar to "show tables" to show tablespace  and log file group?
Also how do i know my table is actually stored in disk?

is there a book or web documentation give detailed information about tablespace, log file group, undo file ,
undo file buff? mysql online doc only tell me how to use those commands to create the tablespace, but did not explain why we need a table space, and to manage the tablespace.

regards