27

Rumors say CDs and DVDs won't remember your data longer than ten years. Are there backup media that do better?

3
  • I've definitely used CDRs that are >10 years old with no issue - but they've also been stored well and not handled much.
    – warren
    Sep 1, 2009 at 11:53
  • > Rumors say CDs and DVDs won't remember your data longer than ten years. I heard 50-100 years for both of them, and this was back when each was still new (i.e., the manufacturing processes—*should*—have improved since then, leading to longer lifespans).
    – Synetech
    Jul 28, 2012 at 3:30
  • I had a CDR unreadable after 16 years
    – Vimes
    Jul 14, 2023 at 2:57

13 Answers 13

12

Hard Drives. Space is dirt cheap these days, you can grab a few TB worth of internal hard drives at a fairly low price. Even external hard drives aren't too expensive.

6
  • 1
    You might think about getting a docking station to go with that, so you can keep buying cheaper internal hard drives and still switch them around easily. Internal hard drives stack better, too.
    – drby
    Aug 28, 2009 at 7:28
  • 7
    Are you sure you will still be able to read a contemporary hard drive in the future? For example, could you connect a 20 year old hard drive to a modern PC to read the data off it? Aug 28, 2009 at 7:43
  • 2
    Ability to read current supports in the future is a big problem of backup, no matter the support. Solutions involves copy backups to newer technologies as soon as they appear and/or keep old systems alive just for the purpose of retrieving backups.
    – mouviciel
    Aug 28, 2009 at 9:33
  • 3
    @ Matthew Lock: there is no way, a hard disc will outlast optical media.
    – Molly7244
    Nov 16, 2009 at 17:34
  • 1
    The other day I connected my last remaining PATA backup drive for testing. The spindle grease was beyond seized. While the data was more than likely fine, the drive had still effectively died in storage.
    – user346081
    Jul 14, 2014 at 7:53
7

Regarding longevity, you'll probably accumulate data too fast for the media to be a problem. 7 years from now you might have enough DVD's to fill a couple Blu-rays. 7 more years and you'll have a stack of Blu-rays ready to consolidate on whatever the next big thing is.

For now, Patrick McFarland's How To Choose CD/DVD Archival Media comes out in favor of DVD+R, specifically Taiyo Yuden's:

To begin with, I do not recommend CD-RW, DVD-RW, or DVD+RW media in any form for permanent storage. This is mostly a no-brainer, but those discs are meant to be able to be changed after burning, and they are simply unsuitable for long-term archival storage. I also do not recommend DVD-R media due to DVD+R’s superior error correction and burning control.

That said, I recommend Taiyo Yuden media across the board. Taiyo Yuden currently manufactures 52x CD-R, 16x DVD-R, and 8x DVD+R media in normal shiney silver, inkjet printable, and thermal printable forms. Taiyo Yuden may be one of the most expensive (if not the most expensive), but their media quality is unsurpassed.

A recent update shows he still affirms this position.

I thought I read somewhere that the Library of Congress uses MAM-A archival gold DVD's but considering the cost I stick with TY's. I usually purchase through http://www.rima.com, while McFarland recommends another vendor in his article.

7

Rumors say CDs and DVDs won't remember your data longer than ten years.

You just said it: RUMOURS! :)

The Optical Storage Technology Association (OSTA) has published the following longevity estimates for recordable optical media:

Manufacturers' estimated recorded life span.

CD-R: 50-200 years

CD-RW: 20-100 years

DVD+R: 30-100 years

DVD+RW: 30 years

BD-R 50+ years

So, chances are that you may not live long enough to prove these estimates wrong! :)

Now compare that to the average lifespan of a platter hard disk (2-10 years). Optical media win that contest hands down.

And then there is the good old stone tablet which will last a couple of thousand years. But the data density of 0.001 kbit/kg is a bit of a showstopper. :P

But in IT, the Cranberry Diamondisc DVD is considered to be the Holy Grail of long term storage, they boast a life span 1000 (one thousand) years. Of course it requires special hardware to burn these discs.

4
  • there's a fair amount of anecdotal remarks on cds not lasting particularly long. Nov 16, 2009 at 17:00
  • YMMV of course, and only one set of backups isn't the best strategy anyway. but recommending platter HDDs instead of optical media because they last longer is plain wrong, they're cheap and fast alright but they're not really a choice for long term storage. they are no match for the longevity of CDs or DVDs. even magnetic tape lasts 6 times longer than the average life span of a hard disk.
    – Molly7244
    Nov 16, 2009 at 17:21
  • hard disks being used or hard disks written to, disconnected, and put in a labelled box? Nov 16, 2009 at 17:43
  • 2
    i don't think that there is much of a difference, it's probably worse if you don't fire up the discs every now and then, corrosion being its worst enemy. hard discs aren't really made for long term storage.
    – Molly7244
    Nov 16, 2009 at 18:32
4

I'm not sure hard drives are any better than CD/DVD long term. The only way to be really sure is to keep checking the data and refreshing it. There are CD's/DVD's that are specifically designed for long term storage but as always these are more expensive.

3

I think it has to do with how much you're willing to spend. I've thought about this in the past and the best solution I could come up with was a NAS with 2 large HDDs in RAID 1 configuration. This way you're protected from HDD failure and I'm pretty sure that Ethernet will still be around 10 years from now. Only worry is if the NAS itself breaks down, so you'd need a quality one.

3

From http://www.superwarehouse.com/HP_5.2_GB_Magneto_Optical_Disk/88146J/p/54344:

HP magneto-optical rewritable cartridges allow virtually unlimited read/write cycles, making them the ideal choice for data management in information-intensive environments. HP write-once cartridges are designed for permanent storage of data that can't be altered or erased. Both disk formats have an archival life of 100 years...

3

I think the question that must be asked is "how long-term is long-term"?

Quality paper is probably the most efficient low-end long-term storage currently known(300+ years).

But if you're looking to archive records in the event of nuclear blast, you might try etchings on metal in a can in a cave.

But if you want to store company records for 50 years, hard disks disconnected and stored in a vibration-less environment together with paper documents on the interface & data formats is not a bad plan.

But if you want to publish historical-class data for the next 200 years, ie, you're investigating for a library or similar institution, you want to make sure that the information is usable when we go to The Hypernet, so you might be investigating a redundant array of cloud data storage centers from different companies with a common query-able interface published on the current Internet.

But if you want to archive historical-class data, you want something that is probably similar to a ROM-style hard disk. (I'm taking a guess that those exist for long-term archive storage).

But are you storing text? video? pictures? binaries? Each of those has different information characteristics and can be stored a little differently.

There's no 'right' answer here until you narrow your focus a bit.

3

Paper backups using an efficient encoding scheme also remain an option. It is not handy and takes a lot of space, but it is robust and long-lasting.

1
  • Paper also degrades with time, just like any other medium. The problem with paper is that you cannot automate curation (ie, repairing bit errors). Indeed, most inkjet printed photos won't even last more than 10 years (the colors will wash out), and the data density is very low (~100KB max with tiny characters and decoding using a computer program). Optical discs are pretty much the same idea as paper but miniaturized, and it can also be automated because there is a norm for writing and reading the data. See a longer explanation and studies here.
    – gaborous
    Dec 28, 2016 at 13:06
2

And now you can store it for as long as 1000 years: http://www.tomsguide.com/us/DiamonDisk-DVD-Storage-Cranberry-Thousand,news-5112.html

2

depends on your data volume

  • USB flash drive- I sill have one 129 MB survived after washing in a machine and after all these years still works. When you start feeling that USB standart start to disapear or speed start to differ too much (i.e. USB 5.0 is the current standart)- transfer to the next new thing before is too late

  • or some skin for CD/DVDs like this

1

The only way to guarantee long life is via redundancy. Keep 2 backup copies of everything, as it's unlikely that both will go bad. Try to vary the media types, for example for DVD don't use the same manufacturer for both copies, or use two hard drive, or one hard drive with DVD/Blu-ray copy. The advantage of a large hard drive is that you can verify it regularly. Also, the SpinRite utility, available from http://www.grc.com/sr/spinrite.htm and costing $89, can recover a hard disk and even refresh it magnetically so the recorded data won't magnetically fade out with time (but it only works on internal drives).

1

Tapes seem to be a good option for long term and big volume archiving.

Slashdot - Offline Storage for Hard Drives?

Flash drives might be worth researching too.

1

DVDs are very good storage mediums, but Blu-Rays HTL (like Panasonic's) are very stable and they are probably the longest lasting storage medium currently available for consumers. They are highly resilient to light degradation and also to humidity to a certain extent. Even big companies such as FaceBook are now using optical discs in automated robotic assemblies for long term cold storage of data.

Blu-Ray discs should last decades, but there is no way to precise the average lifespan of storage mediums more than that simply because either the technology is too new, or because nobody funded such a long running scientific study, so nearly every estimates are done using artificial aging. Artificial aging is very nice to quantify the resilience of a storage medium against natural damages (such as light and humidity, the two biggest factors of degradation), but they can't give a precise estimate on how long exactly the medium will last. I talk about such scientific studies here.

Also, do not believe claims that such medium is going to last for centuries or millenias (such as M-Discs or DiamonDisc) without an independent scientific study behind, most often these claims are baseless (M-Discs have been found to be not more resilient than Blu-Rays, but they are way more expensive! And they also have a defect on the outside plate glue which may make M-Discs totally unreadable in only a few years from now!).

Also, not all Blu-Rays are equals: some brands will be way more resilient than others. And conversely, the optical writer you use will impact the resiliency of your written discs. Refer to studies to know what to choose (if the optical writers are still available...).

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .