Achou -
The implication of increasing the inode count is the growth of the inode file for the volume.
This is also an impact on memory as the inode file is cached.
Increase the inode count with care.
Although you can shrink the inode count in modern ONTAP it's my understanding it still won't shrink the inode file.
There's an old doc TR-3537 that discusses high file count environs.
It's currently marked as 'Confidential'.
If you're under NDA you may be able to get a copy of it.
I hope this response has been helpful to you.
At your service,
Eugene E. Kashpureff, Sr.
Independent NetApp Consultant http://www.linkedin.com/in/eugenekashpureff
Senior NetApp Instructor, FastLane US http://www.fastlaneus.com/
(P.S. I appreciate 'kudos' on any helpful posts.)