Oracle Error Message
RMAN-08112: archived log failover was done on string, check alert log for more info
Reason for the Error
This is an informational message to indicate the server found a corrupted block in an archived log and had to switch to another copy of the same archived log in an alternate archived log destination to get corresponding un-corrupted block.
Solution
If backup is done with delete input option, nothing needs to be done. Otherwise delete the archived log that has corrupted block(s) as recovery on applying this log would fail. Alert log contains name of the log that has corrupted block(s).