Hello,   The 6100E's can definitely be in the same group / pool w/o issue.  Data is striped across members based on their relative sizes.  So a two member pool, where on is 2x the other will have 2/3 of the data compared to the smaller member.     When you add in a new member is does go to the default pool.  However, with out a RAID policy defined it doesn't provide an capacity to that pool.   So after adding it into the group I suggest you then enable on the Ethernet ports, move it to the new pool, then assign the RAID policy.    Regards,  Don 
In each of our server rooms we currently have 2 Equallogic storage pools: - 10K-1GB (2 X 6100X) - 7K-1GB (2 X 6100E) We have just purchased an extra PS6100E and a PS6100XS for each server room. The existing 6100E arrays that we have include 3tb disks and the new one includes 4tb disks. These arrays don't usually have much load placed upon them and are mostly used for mapping network shares or backups / replicas. Can anyone perceive an issue with adding the 4tb 6100E's to this group ? I was planning on deploying the 6100XS in its own pool, as the advice I read was not to mix it with other array types. I'm struggling to remember now, but can you specify a different pool to join a new group member to or does it always go in the default pool first ? If it always goes to the default pool first, is there a way of changing a new pool to become the default pool ?  Thanks   
Logical layout of Equallogic storage pools with new members