You have to trust your backup to a certain extent. The data is likely to change during the actual backup process or during the verification. You really need to ask yourselves these questions first:-
- What are you backing up?
- What is the size?
- How you would recover?
- What is the minimum you need to restore?
- Have you got recover hardware for a server loss?
- What backup catalogues you need?
- Have you secured this all off-site?
- How long does the backup need to be retained?
- Is there a way to freeze the data (switch to backup mode) for databases?
.... and probably a whole bunch of other things.
Media failure is less error prone these days, but in any case there should be an error on the return code you should check for. Consider dual tape backups and/or incremental versus everything every day.
It's too big an overall question to deal with just worrying about how to verify it. It may be that you have answered many of these for yourself already, but if you share what you are planning, you can get a consensus if it is a valid approach or suggestions of other things you need to consider.
Robin