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 example.com, I can quickly point the site to backup.example.com via 401 redirect. This would give me time to troubleshoot example.com while everyone is viewing backup.example.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.
The ultimate solution is two web servers in different locations using BGP to advertise the IPs used; if the primary goes down the secondary will take its place on the same IP in a few seconds.
Depending on your needs, existing infrastructure and budget this may be ideal or impossible; can you give us a few hints regarding your web server setup and what you have to work with?
As for making the backup site this is dependent on the web technology used; it might be as simple as copy some PHP files over and set up MySQL replication, or it might be an expensive as requiring enterprise licensing for Sharepoint and MSSQL.