Longevity of Recordable CDs, DVDs and Blu-Rays (2020)

Totally anecdotal but just a month ago I opened a box from my last moving (ended 4 years ago...) and I found a CD-RW labeled "Backup 2001", which survived 5-6 relocations, even an international one. Well, I put it into an USB DVD player I have aaaand, it starts spinning and spinning and spinning, and nothing shows up in Nautilus. Looking at dmesg I see a few I/O errors on the device. Then, I try ddrescue [1], start extracting an…

Strange that such an article fails to mention M-DISC: https://en.m.wikipedia.org/wiki/M-DISC https://www.reddit.com/r/DataHoarder/comments/zv1nte/mdisc_i... https://superuser.com/questions/1106325/are-m-disks-truly-mo... https://www.reddit.com/r/DataHoarder/comments/yu4j1u/psa_ver...

I like how the CD-R longevity estimate is 20-100+ years, depending on type, which agrees with anectodal evidence. OTOH, they list only 5-10 and 10-20 years for BD-R, while at the same time BR-RE gets 20-50 years, which seems quite questionable. BR-R and BR-RE has been available for years, yet the estimate seems to be based on an "accelerated" study done in 85 days with several cycles of 80°C 85% RH. High humidity high temperature soaks up polycarbonate and could…