Am 14.11.2011 21:12, schrieb Anthony Liguori:
I don't think it makes even sense logically: bdrv_invalidate_cache()
means "throw all your caches away and refetch everything from disk".
What do we gain from doing this on stop? To some degree I could
understand if you did it on cont, so that you can modify an image on the
host while the VM is stopped (though I would still consider it criminal
:-)).
Michael basically was trying to avoid having a VM's state change after you
stopped the guest.
With something like cache=unsafe that periodically flushes based on a timer (I
think), you want to make sure that that doesn't happen after stop occurs.
This is a good point, but neither does cache=unsafe use a timer nor can
I see how invalidating the cache would avoid such behaviour. And
throwing away any unwritten changes doesn't really make it better.