1. A computer-implemented method of providing data high availability to a set of host computers, the computer-implemented method comprising: while a production array provides the set of host computers with access to a production logical unit of storage (LUN), replicating data from the production LUN to a replicated LUN on a replication array, wherein the production LUN resides in a particular storage pool and wherein the particular storage pool in which the production LUN resides comprises a critical storage pool that is one of a plurality of storage pools located in the production array; after replicating at least some of the data from the production LUN to the replicated LUN, electronically detecting (i) a production array deficiency and (ii) that the replication array is sufficiently healthy to operate as a production site, wherein detecting that the replication array is sufficiently healthy to operate as a production site includes performing an internal health assessment on the replication array that determines that a critical storage pool that is one of a plurality of storage pools located in the replication array has more free storage available than the critical storage pool located in the production array; and in response to electronically detecting the production array deficiency and that the replication array is sufficiently healthy to operate as a production site, automatically performing, by electronic circuitry, immediately and without user interaction, a failover operation which (i) terminates providing the set of host computers with access to the production LUN and (ii) provides the set of host computers with access to the replicated LUN on the replication array, wherein automatically performing the failover operation includes initiating the failover operation in response to a result of an internal status assessment of the production array indicating that the production array has the production array deficiency, and wherein initiating the failover operation includes i) discovering that a level of remaining free storage in the particular storage pool has reached a predefined threshold, and ii) commencing the failover operation in response to discovery that the level of remaining free storage in the particular storage pool has reached the predefined threshold.