First off, is your requirement ease of managing capacity or performance? If performance then stay with raid groups, there is always more overhead with Pools.  For best performance Reserve LUNs should stay in traditional raid groups and do not enable FAST cache for those.  Create Pools for different types of usage. Just like with raid groups, if you want the best performance you should not put a lot of different types of applications in the same pool. If you have heavy random Write apps, then create a R10 Pool. If you have Database apps, then you should probably have two types of pools - R10 for the LOGs and Temp (no FAST cache ) and R5 for the database (FAST cache good for this).  There's a lot of good information in the FAST VP White Paper (two attached). See page 32 in the Oct 2011 White page for Best Practice recommendations.  glen
Hello -   We have a CX4-240 running FLARE 30.  Our goal is to collapse existing traditional RG/LUNs and migrate to FAST VP Pool.  The array has the following types of drives:  450 GB FC, 600GB FC, 600GB FC, 1TB SATAII.  FAST Cache is enabled on a couple of 100GB SSDs.   We currently have an existing pool with 8x 1TB drives, and 8x 600GB FC drives.  We'd like to expand the pool by adding the rest of the drives in the array after migrating/collapsing the traditional RGs/LUNs.   What is the best practice when it comes to FAST VP pools?  According the EMC documentation, a pool can include all disks in the array.  This is the path we are leaning towards; 1 pool with all disks in the array.  Is this something you folks see out there?  Multiple pools?  Also, we will be enabling Snapview in the array as we will be configuring it for Commvault's Snapprotect.  Do you see any issues with creating Reserved LUNs off of FAST VP Pool/s?  For the Vault drives, I am thinking of leaving those on traditional RG.   Thanks for you input in advance. 
Best Practice - # of Disks in a FAST VP Pool