Troubleshooting a slow RMAN backup

(As I always do, the names of the databases and files are not the real ones, but the numbers are).

Yesterday we got a complain for one client. He said that the RMAN backup of the database was running on working hours and that should not be. I looked at the times of the backup along the week and saw that the backup took much longer than expected.

Recovering a deleted datafile using lsof

Here is a little trick that can be useful in case of a accidental delete of one datafile.
I do not recommend or encourage anyone to do it, but could be useful under certain specific situations.