When it comes to backups, I never rely on CD/DVD's, because those are deteriorating all by themselves. I've lost numerous files over time.
That's why I rely on pocket-size HD's, replaced every 2, 3 or 4 years. And each is connected only at backup time, or at the moment I want to replace it.

That plus a NAS (Synology)
And I rely for this on batch files that uses one of the very best tools from Microsoft, since Windows 1.0: Robocopy. A pure DOS-based, extremely reliable tool.
But indeed, that's for Microsoft-based systems.