Well, using 80-pin SCSI hotswap drives for terabyte backup wasn't exactly what I recommended. The biggest HDDs for my servers with 80-pin hotswap bays are 18GB ones. I'd need literally one thousand or more units to backup my data which would probably cost well over 200,000 USDs. I have only two 80-pin drives. SATA II options are far easier, cheaper, and faster.
DVD+R/-R media are write-once. Write-once means it's permanently stored. That's the difference between rewritable HDDs and recordable DVDs. It doesn't mean the data recorded on DVD disks are safe just because it's write-once technology. For data longevity, get Blu-ray media with protective cartridges. Lots of Japanese companies and invididual consumers have used Blu-ray because of larger capacity and data safety.
Anyway, there are cheap and good DVD media like those ghetocowboy mentioned above to consider instead of cheap and bad DVD media.