Sry, but I disagree, the only acceptable backup is a template.
@chrisyts
Here is a short description:
The idea is: instead of having one huge project with too many pages you will create several smaller independent projects.
If you followed the links gotfusion posted you found out how to create templates.
You can split your project into smaller sections by creating templates of parts of your website.
Go to Site View, hold Shift and mark the pages you want. Then you export them as a template.
From these templates you can create new websites. (gotfusion´s second link)
Make a plan for start.
The first template/”new site from template” will be for your main project with a few important pages.
This will replace your website which is on the server now.
And then you will have created several smaller projects with the rest of your huge website.
Let´s call them Part1, Part2…….
They have to be uploaded onto your server as well.
So take a 3thd party FTP client like Filezilla e.g., connect to your server and create new folders/directories on your webspace.
Call them Part1, Part2……
So if you want to upload your Part1 in the end with NOF the Directory in the Publish Settings has to be: /Part1.
The URL for Part1 would be www.yourdomain.com/Part1/
But….the major task comes before.
Before you will upload all your small projects you have to link them.
That means for each one of them you have to create a Custom Navigation with External Links.
Hopefully you know how to make a custom navigation with external links.
If not, ask again. And hopefully your navigation is sitting in the Masterborder Area, so you have to do it only once per project.
This might sound like a lot of work, but it´s not.
And in the long run it pays.