What is the difference between fault tolerance and failover?

Question

I'm guessing Failover is plan A in case of wide system failure, and Fault tolerance is plan B in case plan A fails?
somebody please confirm this.

Answer 1

Failover usually means switching to a totally duplicate system if one fails. Generallly it refers to computer systems or fully redundant spare systems. Technically, some Raid could be considered failover, if a disk fails, another takes over, like Raid1.

Fault tolerant just means if any one component fails, there is a spare unit to take over. This usually applies to disks as an example, raid5. You generally need many diffferent fault tolerant systems to build a full failover system.

Answer 2

That's not really the case, but the terms are related.



Fault tolerance refers to a system's ability to keep operating in spite of problems occurring.



Failover refers to two components, each capable of performing the same function, where each of them is set up to completely take over the particular function in the event that the other one fails.



It's not so much that one is "Plan A" and the other is "Plan B", but that one is a subset of the other: Failover could be considered one type of fault tolerance.

Answer 3

Difference Between Failover And Failback

Answer 4

I had also asked this same question 3 times, and did not receive a good answer

Answer 5

This is interesting