Since disk failure can impair system security, you can include the waitfor mirrorexit command in an application to perform specific tasks when a disk becomes unmirrored:
begin waitfor mirrorexit commands to be executed end
The commands depend on your applications. You may want to add certain warnings in applications that perform updates, or use sp_dboption to make certain databases read-only if the disk becomes unmirrored.
Adaptive
Server knows that a device has become unmirrored only when it attempts
I/O to the mirror device. On mirrored databases, this occurs
at a checkpoint or when the Adaptive Server buffer must be written to
disk. On mirrored logs, I/O occurs when a process writes
to the log, including any committed transaction that performs data
modification, a checkpoint, or a database dump.
waitfor mirrorexit and the error messages that are printed to the console and error log on mirror failure are activated only by these events.
