I understand that expansion shelves are treated as their RAID group. I am trying to understand how this plays into an environment where multiple storage controllers may be combined in the same storage group where data is being striped across multiple storage arrays. Ie. 1 x CS460x2 + 1 HS65, being combined with a second CS460x2 My assumption is that the expansion shelf would be recognized and managed as a separate storage pool in the same storage group and would be independent of the 'combined' storage pool shared between multiple arrays. Is this correct?
I have seen the documentation around scale-up and then scale-out, but none of these documents takes into account a single array with multiple expansion shelves, being combined with a second, third or fourth storage array with no expansion shelves.