Thanks Alan

I didn't know if some sort of "interrupt" came back from the device
that notified CP that a FlashCopy was taking place.

I haven't got that far in flashcopy, but I am under the assumption that
if you need to flashcopy a series of volumes at the same "instant" in
time, I can't do it from VM, as each volume takes an individual
flashcopy command.  Hence the first volumes "flash" is started several
seconds before the last volumes "flash".

The web interface of bundling a series of flashs together, seem to
indicate all volumes will be flashed at the same instant.

But I do recall something about I can set up a flash, using DSF to
do....something...  But I haven't needed to get to that point yet.

Tom Duerbusch
THD Consulting

>>> [EMAIL PROTECTED] 12/6/2005 9:26 AM >>>
On Monday, 12/05/2005 at 11:36 CST, Tom Duerbusch 
<[EMAIL PROTECTED]> wrote:
> I have been using flashcopy for some interm backups that I restore
from,
> also using flashcopy.
> 
> So, if I have been using device 150, and I do a flashcopy from 1150
to
> 150, what happens to the MDC contents for 150?

If you use the CP FLASHCOPY command or a guest initiates a "virtual" 
flashcopy I/O, CP will handle the cache.

If you go behind CP's back to do the flashcopy from the disk controller

console then you are in trouble.  The controller does not notify the
host 
of "background" activity on a volume and the cache will not be valid. 
So, 
if you use the controller console be sure to SET MDC FLUSH <vdev>
before 
you start reading/writing the minidisk again.

Obviously it is far better to initiate a flashcopy from CP.

Alan Altmark
z/VM Development
IBM Endicott

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