Wondered if we could get a discussion going about the merits of different "deep" storage strategies for a large image file archive?

I currently use removable SATA drives that backup the working drives, and am about to put in place a second tier of security, to be stored off-site.

DVDs are an option that's been suggested as more bulletproof than HDs. We're talking a collection in the tens-of-thousands of hi res images, so the burning time alone is daunting. Not to mention access and restoring in the event of a disaster.

I've also heard very a compelling case made that modern HDs are so reliable that their inherent vulnerabilities are almost moot, especially if treated carefully (key word: almost... ) Without going completely obsessive/compulsive, remember there will be two backups of everything.

No simple answer, I know. And anything done now would obviously be re-visited in the future if new technology were to offer a better answer. Anyone have other ideas?