You can add disks to an already existing pool in disk packs. In case of a RAID 10 pool, you would have to add another 6 drives when you want to expand the pool. This is enforced through Unisphere.
Hi,  One of my customers has a requirement for 8 disks in a RAID 1+0 configuration on a VNXe 3100. One of their app vendors is requesting it.  The default storage pool creation on the VNXe creates a 3+3. Is it possible to add 2 more disks to the storage pool after creation to make it 4+4 ?  If so, is this the same for all storage pools including RAID 5? If you had 4+1 and added 5 disks after creation you would have 9+1.
Storage Pool Creation