The joy of the impermanence of digital data in the real world. ;D
Tape backup? Seriously, even when buying the most expensive equipment and tapes, I always had it fail when it was most needed and ended up using a secondary backup system to do restores.
DVDs are untrustworthy unless you do a less than maximum speed write to allow the laser time to burn the bits and then do a data verify after the disk is written.
Which leaves you to using some sort of USB hard disk method to do backups, preferrably two separate ones so you don't get bitten by hardware failure of either device (once again bloating expense and time required).
And have yet another system where you can do periodic data restoration and comparison to make sure your backup method A) works and B) is capable of restoring the data to a new system. Nothing stunk so much as having the need to restore an old tape and finding that in the duration, head wear and tolerance meant the tracks were displaced so the tape was unreadable, despite the fact you could read one done last week. One particularly painful restore required about 5 retensions to get one good read off the tape, after which it failed completely to be readable. DAT cured that problem, only to bring on a new set of failure modes.
I've come to believe in data spew, throw it in as many locations as possible and rebuild the core storage from the distribution when the system failure occurs. If something happens and takes the whole building out, you're not much going to care anyway.
And also learn to recognize garbage data needs to just be bitbucketed. If it isn't there, it ceases to be a concern.