I take yearly backups on to Blu-Ray M-DISC discs. They're ceramic instead of organic so they're not susceptible to the same kind of oxidation issues most regular optical media has. I make a few copies of the last couple of years of important documents and images (I get some overlap) and store those at a few different locations. Usually other family members I trust.
The amount of important documents and images that I really care about is only a small percentage of all my data. Most of the two year combinations fit on a single 25GB disc but its not terribly expensive to get a 50GB or 100GB disc if needed.
Of course, there's a chance I won't be able to find a Blu-Ray reader in 20-30 years but I imagine there will be some other way to transfer over this dataset when that time comes.
As to the durability of these M-DISCs, I have three 25GB discs I've been testing durability of over the last several years. One sits somewhere outside, often somewhere around the patio table or on a cart under some shade unprotected. Another kicks around on my desk unprotected and gets moved around a lot. Finally a third one sits in the same disc case with the actual data I'm trying to preserve. All of the discs have the exact same data. Every now and then I compare them. The outside one has definitely had a bit of corruption but is still mostly readable. The desk one has a couple of files that it does some retries on (the seek time to the file is higher than expected) but has no corruption. The one in the sleeve is practically perfect after several years.
The amount of important documents and images that I really care about is only a small percentage of all my data. Most of the two year combinations fit on a single 25GB disc but its not terribly expensive to get a 50GB or 100GB disc if needed.
Of course, there's a chance I won't be able to find a Blu-Ray reader in 20-30 years but I imagine there will be some other way to transfer over this dataset when that time comes.
As to the durability of these M-DISCs, I have three 25GB discs I've been testing durability of over the last several years. One sits somewhere outside, often somewhere around the patio table or on a cart under some shade unprotected. Another kicks around on my desk unprotected and gets moved around a lot. Finally a third one sits in the same disc case with the actual data I'm trying to preserve. All of the discs have the exact same data. Every now and then I compare them. The outside one has definitely had a bit of corruption but is still mostly readable. The desk one has a couple of files that it does some retries on (the seek time to the file is higher than expected) but has no corruption. The one in the sleeve is practically perfect after several years.