In early days of ERP boom, in one of the companies where I worked, ended with an Informix DB running on HP-HA disk array with RAID 5 enabled. We done that because of the ERP vendor recomendations. The system working well even in the case of one damaged disk It worked as expected: while one drive down, the information was still available. Of course we were satisfied with the investment on the solution but as soon as we replaced the hot swap damaged disk, and the information started sync, somebody asked this question: what happen if we lost a second drive?
I´m telling this story due to, the Steve´s comment about, even with the primary node was restored, we don´t end the disaster mode, until we replaced all the array disks with new ones (one each time), and reconfigured our db to RAID 1.
It took us about 1 month to officially ended the disaster mode operation.