Hello,   The volumes that make up the container aren't manageable in that way.  It will distribute the space across the members based on their relative sizes.  You can't select which one it will use.  The 6510E being so much larger most of the reserve will be on the 6510.  
Hello, suppose my EqualLogic group has a storage pool consisting of a PS6510E array with RAID6, and a PS6210S solid state array with RAID6.  I have a FS7610 NAS appliance.  Suppose I create my NAS reserve in this storage pool.  Is there any control I have over which member the NAS reserve resides on?  How does that work?  Thanks.
Where is NAS reserve located in a multi member pool?