Graeme writes:
> What about the batch programs eg SCOPE.  It runs the MI all the time - what
> overheads does it place on the system compared to Glance/CIA etc??  Is the
> overhead in having the MI running, or how the process itself uses the MI??
 
The overhead is in simply having the MI turned on.  Any work the
performance tool does in *addition* is extra!
 
BTW, my comments about the MI aren't meant to dissuade people from
using MI-based tools...they are valuable additions to a system managers
toolbox.  However, the user should know that they impose a varying amount
of unobvious overhead on the system.  I'd almost never leave one running
continuously, since the demonstratable overhead is too high for my taste.
 
--
Stan Sieler                                          [log in to unmask]
                                     http://www.allegro.com/sieler.html