Toasters, I am setting up a new A400 that came with 3.5 disk shelves (3 shelves with 24 disks and one shelf with 12 disks), for a total of 84 disks.  Setting the partitioning bit aside (I think I have that right..), I configured raid group sizes of 20, two groups each into two aggregates, one on each controller.  This uses 2 x 2 x 20 or 80 disks and leaves 2 spare disks on each controller, which are actually 4 partitions per side spread out on the SSDs. There will be an issue if we order SSDs to fill the half shelf.  There would be no way to add these disks to the existing aggregates and not have really lopsides RG sizes.  But if I expanded each of these raid groups by 2 or 3 disks and added the new disks manually, it would work out great. Is this the best practice for adding disks?  Wouldn't that scheme leave data "stranded" on the existing disks?  Does this matter even with SSDs in light of the performance per disk. Thanks, Fred