I have a CentOS server which at times either crashes or gets attacked with DDOS. At the moment I have an off site backup which is filled up with 1.7TB of data. I'm currently paying as much for the backup as I am for the server and I was looking for advice from experienced people as to what option is best to proceed from here.

Would it be a viable solution to ditch the offsite backup, and instead purchase an additional server which is an exact duplication of the first server. So if the first server is down, users are re-routed to the second server without noticing the first server is even down. This would create an automatic backup of the first server (albeit not offsite) and relinquish the need for the expensive offsite backup.

Is the above solution a true solution to pricey backup or is offsite backup absolutely necessary? How would I go about doing this (obviously it's pretty complex so just links to some reading material or the terminology of the procedure would be great)?

Appreciate the help and advice.