[codezero]

Just anecdata, but I had this concern when I worked in academia and we backed up all our data to writable DVDs. I was there 10 years after the start of the project and I periodically checked the old DVDs to make sure they weren't corrupted.

After 10 years, which was longer than the assumed shelf life of writable/rewritable DVDs at the time, I never found a single corrupt file on the disks. They were stored in ideal conditions though, in a case, in a closed climate controlled shelf, and rarely if ever removed or used.

Also, just because I think it's funny, the archive was over 4000 DVDs. (We had a redundant copies of the data compressed and uncompressed, I think it was like 3000 uncompressed 1k compressed) there was also an offsite redundant copy we put on portable IDE (and eventually SATA) drives.

[Spooky23]

Thank your procurement agent and hvac guy.

My team used to maintain go-kits for continuity of operations for a government org. We ran into a few scenarios where the dye on optical media would just go, and another where replacement foam for the pelican cases off gassed and reacted with the media!

[codezero]

I was the procurement guy for many years, and we had no HVAC guy - we were in a state university, and there was nothing special about the DVDs we bought, they were from Newegg and other retail places, we did buy the most expensive ones because our grants allowed us to, so maybe that's a factor.

I have no doubts (hence my anecdata statement) that there could be bad DVDs in there, or that maybe over a longer time horizon that the media would be cooked.

[accrual]

Wow! That's pretty interesting. I can imagine wanting to store optical media in Pelican cases or similar for shock protection, ability to padlock, etc. But yeah -- what's the interaction between whatever interior foam they chose and the CD-R media and dyes? Especially after 10+ years of continuous contact?

Optical media is probably best stored well-labeled and in metal or cardboard box on a shelf in a basement that few will rarely disturb.

[Spooky23]

It was a really fun project. We basically made these disaster kits, with small MFPs, tools, laptops, cell radios and INMARSAT terminals hooked to Cisco switches (this was circa 2002-3) and a little server. We had a deal that let us stow them in unusual places like highway rest stops.

We’d deploy them to help respond to floods or other disasters.

One of the techs cooked up a great idea — use Knoppix or something like it to let us use random computers if needed. Bandwidth was tight, but enough for terminal emulators and things like registration software that ran off the little server. So that’s where we got into the CD/DVD game. We had way more media problems than we expected!

[hmstx]

Most of the CDs we burned at home in the 1998-2005 era were still good in recent years, some DVDs in there too. Luck, I guess. No delamination or rot. Really, my main problems were figuring out file types without extentions (burned on classic Mac OS) and... appropriate programs to open them (old Painter limited edition from 1998 needs... the same thing, pretty much).

OTOH, some 12 years ago I worked IT at a newspaper and we were moving offices. The archivist got an intern in a room in our section of the building and together they spent a month or two scanning, then committing whatever physical media to burned CDs (maybe DVDs) before chucking the former to the bin. Maybe a year after the move, a ticket was opened and I went to check the disks. None of them worked, CRC failures all over. I don't think they even considered testing them, or burning duplicates, or maybe they used a really bad drive which would produce media unreadable by anything else - although I'm only aware that this is a thing with floppies for example.

[accrual]

Cool tale! I have observed a mix of viable and unreadable user-burned CD media from the late 90s and early 2000s. It definitely depends on the quality of the media, quality of the burn/drive/laser, and how well it was stored interim.

My oldest disc is some bright blue Verbatim disk my childhood friend made for me so I could play our favorite game at home pre-2000. I have a bit-perfect copy, but the actual disc still reads fine in 2025 when I last tested it.

[codezero]

Yep, quality is definitely a factor here, as much as it can be. We had NSF funding pre-2008, so there was plenty of budget for quality media. We spared no expense, and while I stayed in a $60/night hostel in SF for conferences, our rewritable DVDs were the best money could buy at the time lol.