Hi,
I am not sure if I understood the question completely.
I am not really sure how any configuration on the device can help you if the actual device fails completely.
With regards to the hardware I think only the high end model with SSP-60 comes by default with 2 PSUs while others come with 1 PSUs though you can install a second PSU to the units and in this way provide some redundancy in the event of power failure though that naturally depends on other factors than the ASA alone.
To my understanding it is also possible to set up the single ASA 5585-X unit with dual SSPs. I have not had to set up such an environment so I am not sure how it exactly works. I am not sure how they handle together. I can't seem to find the document I was once reading about this. But I would imagine that this could provide redudancy to the firewall setup.
Then there is also Clustering ASAs (not same as Failover pair) units but again this naturally requires additional hardware and is something I have not setup up myself.
Then there is naturally configuring 2 identical ASA 5585-X units in Failover pair (Active/Standby or Active/Active) to provide redudancy in case of hardware failure.
We have some less critical environments set up with single ASA5585-X units and we naturally dont guarantee the same availability for those services as with setup where we have 2x ASA5585-X units in Failover. We do have replacement units for these and can naturally get replacements otherwise also.
- Jouni
