I'm deploying my first VNX (5300) in the next week or so, and have gone through the Quickstart training, but am still fuzzy on a couple of critical details regarding configuration options.  I would really appreciate any help with the following:

1.)  Vault Drives -  The first 4 drives in my DPE are used for the VNX OEs (understood); however, I get the impression that the ability to use capacity of these drives depends on whether you opt to use RAID Groups or Pools.  I have read on this forum that if you provision traditional RAID groups, only a small portion of the vault drives is reserved for the VNE OEs for block and file, and the rest is usable capacity.  Conversely, were I to choose to create pools on my DPE, those drives would be completely unavailable for data use.  I get this from the EMC VNX best practice document on storage provisioning (page 94):

"The maximum number of drives in a storage pool is storage system model-dependent.  It is the maximum number of drives for the model, less the four drives of the system drives (Only entire drives may be provisioned in pools)".

Can someone confirm this please?  And if this is the case, is it standard practice when planning on using pools as opposed to the 16-drive-max RAID Groups, to just purchase 4 of the smallest available drives for vault usage?

2.) The system I have been shipped includes 24 600G 15k SAS drives (15 in the DPE, and 9 in the first DAE).  My client would like the performance of RAID 10 with these drives.  In this case, I obviously cannot create a single RAID group given the 16-drive limitation, so I am considering using a pool.  This creates a problem, because if the answer to my first question is "yes, that is correct", then I only have 20 drives available for the pool, which is not a number evenly divisible by 8 without remainder.  According to the best practice document, this is not recommended because the pool would be made up of 2 8-drive RAID 10s and a single 4-drive RAID 10 (correct?).  If I were to designate 2 drives as hotspares, this would be 2 8-drive RAID 10's and a 2-drive RAID 10 in the pool (correct)?  Is this that big of a deal from a performance perspective?  What are the scalability implications?  Say, for instance, I wish to add another DAE in the future with 8 more drives in it, and add them to the pool, would this then mean that my pool was made up of the first two 8-drive groups, the single 4-drive group, and then a newly added 8-drive group in the second DAE?

3.) Can FAST VP be added at any time to create a 2-tiered pool?  If I create this homogenous pool now, may I later add some NLSAS or Flash drives in a new DAE and enable FAST VP?

4.) If the answer to my first question was "no, vault drives can also be members of a pool", then I guess there is no problem because I will then have three 8-drive RAID 10's to make up the pool (though I should probably add a hotspare).

Thanks in advance!