This is a single context active/ standby pair. The standard procedure for upgrade is download image to both units and reload the primary and then the secondary before primary comes back. My concern is that if a problem occurs (say corrupt image) or something else, which means neither device comes back, we will have extended outage before we can down grade and roll back the configs.
Is it possible to do one unit at a time by setting "no failover" on both devices and then upgrading individually. If so, should we do the active or standby first. Also, will the reload cause failover to re-enable thus making this method not possible.
Many thanks in advance for any assistance and clarification - Steve