I've stopped using burned CDs and DVDs like 15 years ago, long before they were considered obsolete, after losing a huge amount of data, including multiple backups of projects. All of them were kept in their own case on a wall CD/DVD holder, no weights, no humidity, no excessive heat or any sun exposition. After only about 5 years like 30% of them were unreadable at all and others developed errors, so as soon as I realized what was going on I backed up everything I could to hard drives in multiple copies, dumped them all and stopped using that media completely.
Printed media last a lot more, but those CD/DVD R/RW to me are too unreliable to be used for anything beyond the occasional OS image install where USB boot isn't available.
Like DNA or living organisms: digital data has to be kept "live" to truly be secure, replicating itself somewhat regularly. Attempts to store it statically are cost-prohibitive or fail at much higher rates than claimed. Worse if the technology is on a down-hill trend because manufacturers focusing on quality are the first to go out of business (higher expenses in a shrinking market).
You can ask the Floppy King about that - near the end of 3.5" floppy manufacturing they saw astronomical rates of failure, 30-50%.
Similarly the quality of CD-Rs definitely took a nose-dive. I'm fairly certain the tail end of "20+ year" CD-R/DVD-R discs won't last as long as claimed but YMMV.
I'm not sure about this being the reality forever. Ever now and then we find some very old scripts or other ancient artifacts containing data from times already forgotten (at least on "basic" human language). If you want something to live eternity just etch the bytes into a stone or print it in some age resistent material.
Of course we can still hope on a easily writable medium that would be also very resistant to ageing.
Given the right context I even think that information produced by humans can outlive earth itself[1]
Sure - but with HDDs, you tend to just move all your stuff during each update cycle, because the new generation then tends to have a multiple of the capacity you've had before.
CDs/DVDs/... feel very much more like a "long-term" storage solution, even when it isn't. Maybe it's because you can put them in shelves and forget about them, much like books?
Plus your backup probably requires dozens of CDs and DVDs, and perhaps they then fit on a handful of 4TB drives, and perhaps now they fit on a single 20TB drive.
For me, my storage needs increase more or less linearly, but storage capacity increases exponentially, making every cycle easier, involving less drives.
This is also true. Having also lost data on two hard drives kept in a drawer for just over a couple years I can totally confirm that, however it was a isolated incident probably also due to some physical issues in the drives, although they weren't old and SMART would report them as 100% healthy. After those two years both drives were completely dead, not just unreadable; ultimately I could bring one to life again after removing and carefully cleaning the controller pcb; however it still required a complete reformat as the data was gone, while the second remained dead. Now I rotate them so that every few years I copy all data to new disks while keeping the old ones until the next rotation: half of my NAS drives become offline backup disks, the other half I use as spare backup disk (with aggressive spindown etc) in some PCs, so I have both live and offline backups. Data should be safe, hopefully:)
Wondering if you do any checking for bitrot? I mean, if some files on one of your disks became corrupt over time how would you know before it becomes too late to recover it from older backups?
I'm no sysadmin so my knowledge in the field is limited. I'm relying on ZFS mirrors which hopefully should be a bit better than the alternatives at bit rot protection, but admittedly if I was hit by corruption at that level that would catch me unprepared. I'm open to suggestions however.
> I'm no sysadmin so my knowledge in the field is limited.
Same here, but my primary backup is also using ZFS mirrors. I have one cronjob that once a month runs 'zpool scrub mypool' to validate all checksums as a bitrot test, and then a day later another one to email me the results of 'zpool status'. If that email contains "state: ONLINE" then no issues were found.
But I've pieced this together myself and would also be open to anyone's suggestions!
If you keep a domestic model running 24x7, you are probably right. But if you just do cold archive, my last check were after around 12 years, all drives spinned up normally without any issue. No noticeable data loss at all.
Out of simple anxiety, I transferred data from a few drives (spanning 2007 to 2015). If there were any issues, neither my file manager nor the SMART status reported any.
My hardrives are in a ZFS z2 array: I have already survived one total failure with no dat loss. I not protected against fire, but overall my data is safer than ever.
Those are BD-R. According to the linked research, those will last 5-10 years, or up to 20 years if you're using a gold metal plate. Either way, they're not close to top performers that last 50 to 100 years and more.
I'd suggest creating multiple backups, including additional mediums such as hard drives and cloud storage (something like S3 Glacier Deep Archive could be relevant), and refresh the media periodically.
They aren't normal BD-Rs nor are they gold plate. They use a different technology for the reflective and recording layers. These discs weren't included in the linked research.
>They literally engrave data into a polycarbonate with high melting point instead of writing to a dye.
Are you sure you're not talking about pressed (ie. mass produced) discs? I find it unlikely that a blu-ray/dvd burner equipped with only a laser can "engrave data into a polycarbonate with high melting point".
> Verbatim M DISC™ optical media is the new standard for digital archival storage. Unlike traditional optical media, which utilize dyes that can break down over time, data stored on an M DISC is engraved on a patented inorganic write layer – it will not fade or deteriorate. This unique engraving process renders these archival grade discs practically impervious to environmental exposure, including light, temperature and humidity.
Me seemed to be a little bit luckier as only 80% seemed problematic after around 10 years. But the result were the same, I had to dump all of them directly except those I did not wish to lose. But even after multiple attempts, still suffered very significant loss.
