Awesome, glad it was informative.
So I did get some internal feedback and need to make a small update above. It comes down to keeping the math simpler than what I had noted, specifically about factoring in the pool LUN overhead. It is, per an internal PPT, already accounted for in the 5% or 10% free.
When I mentioned above about FAST VP configurations:
1) allocating (up to) 90% of the total pool capacity for block
2) dedicating 95% of the total pool capacity for filestorage
the remaining 10% or 5% free (respectively) is already accounting for pool overhead from what I recently read. I, on the other hand, had suggested that you want to calculate it up front. Not technically wrong, but basically it comes down to keeping the math simple.
Therefore, to use an example:
1) For instance, say you have a pool that you want to, per bp, dedicate entirely to filestorage with a total capacity of 10000GB (3 tiers w/ FAST VP).
2) Then using the rules above, you determine that you need 25 LUNs
3) 10000GB / 25 * .95 = 380GB
Therefore, you would simply create 20x (thick) LUNs of 380GB each instead of factoring in the pool lun overhead ahead of time. Again, keep it simple.