update stand-by server

hi all ,

we are in the process of migrating from one system to another.

i have some questions/concerns and i hope that u can help me with.

1) . we are in the process of merging to seperate system together , these applications run on 2 seperate sunfires . after the merge we will have one system running both applications .
2). we setup a v890 Server that will be used as a stand-by in case of a problem occured .
the problem is how to keep the v890 up-to-date with the sunfires !!!
i was thinking of port mirroring on a switch !!!
is there any easier way or any idea that could help me in the design ....

please note we are not utilising RAC for oracle databases .
really appreciate ur help

cheers
ppass