I have a website which is very large and has a large user-base. I am trying to think of a 'best practice' way to create a back up or mirror website, so if something happens on domain.com, I can quickly point the site to backup.domain.com via 401 redirect. This would give me time to troubleshoot domain.com while everyone is viewing backup.domain.com and not knowing the difference.

Is my method the ideal method, or have you enacted better methods to creating a backup site? I don't want to have the site go down and then get yelled at every minute while I'm trying to fix it. Ideally I would just 'flip the switch' and it would redirect the user to a backup.

Any insight would be greatly appreciated.