PSA: Rescue those old backups before disc rot renders them useless

Shawn Knight

Posts: 12,388   +121
Staff member
The big picture: If you’re like me, you’ve got at least one spindle or binder full of custom burned optical discs tucked away in the closet or safe. While these data gems may be shielded from most physical calamities, it’s important to remember that they aren’t impervious to Father Time.

Disc rot, or the tendency of optical discs to become unreadable, is a very real thing. Common causes include, but aren’t limited to, physical scuffs on the bottom of the disc, damage from ultraviolet light and reactions to contaminants as well as the de-bonding of a disc’s adhesive layers and oxidation of the reflective later, both of which happen organically over time.

In essence, your collection of disc-stored data is a ticking time bomb that could be on its last leg (if not already gone).

There are a lot of factors to consider when estimating the longevity of recorded discs including their manufacturing quality, how the data was recorded onto the disc and how they were subsequently handled and stored.

Disc formats also factor into the equation. According to one study conducted by the Canadian government, discs can last anywhere from five to 10 years on the low side and north of 100 years in an optimal situation.

As How-To Geek highlights, recordable discs like the ones you may own could easily be between 15 to 25 years old at this point. If they contain data that isn’t backed up elsewhere, now would certainly be the time to look into addressing the issue.

The easiest way to go about backing up old data is to simply copy the contents of your discs over onto a hard drive, solid state drive, flash drive or online storage locker. This can be done easily enough using a computer with a functional optical drive and an attached storage device. Optionally, you can elect to make an image of the disc which copies the entire file structure of the disc, complete with any file systems that might be on it.

In the event you come across what appears to be a bad disc, don’t lose hope. Try accessing the data from a different drive or a different computer – heck, as many as you can get your hands on before reasonably calling it quits. And if you’re desperate enough, apps like IsoBuster may be worth a shot as a last-ditch effort in the recovery process.

Hopefully, it doesn’t come to that and you’re able to get everything backed up onto a more robust form of storage before it is too late.

Image credit: MoSiwa, marymyyr

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HIC99

Posts: 28   +16
So I still use CDs for my music, and I do rip them when I get the disc, but I have purchased older CDs and games (like og half life and counter strike) from thrift stores all the time and I haven't really encountered this issue. Not to say that it isn't a problem but I am not too worried.
 

Waikano

Posts: 12   +12
So I still use CDs for my music, and I do rip them when I get the disc, but I have purchased older CDs and games (like og half life and counter strike) from thrift stores all the time and I haven't really encountered this issue. Not to say that it isn't a problem but I am not too worried.
I think the issue is with "burned" CDs not manufactured ones, I've never heard of Manufactured CD/DVDs going bad....only scratched :-/
 

Lew Zealand

Posts: 1,468   +1,438
TechSpot Elite
I ripped my dad's CD collection a few years ago and out of about 1000 CDs, 3 were unreadable in any player. So factory pressed CDs can go bad over 10-25 years but the rate is very low. I also copied off my old CD-Rs about 6 or 7 years ago, which were about 10 years old at that point and pretty much all of them (about 50) were still good. I'd also done ~80 DVD+R recordings of older then-unavailable videotapes and 100% of those were OK but they were only 5-6 years old at that point. And all the shows on those DVD+Rs are now available in a much better format than 2nd-gen videotape sources, so wasted time and effort. The learning process of stripping MacroVision was cool, though.
 

QuantumPhysics

Posts: 3,044   +2,860
Some of my old DVDRW and CDRW have faded right through where you can see through them.

I sat with them and copied them one by one to my NAS’ HDD.

Once SSD got cheaper, I transferred all that data to a 4TB SSD.

As SSD gets cheaper I can move those backups and my new stuff to a single 8TB SSD.
 
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Neatfeatguy

Posts: 45   +48
I have burned CDs from 15 or so years back that have been sitting in a CD case in my car for those many years. The discs still work - I pop them into the CD player (who'd a thunk my new(er) 2016 car I just got would still have a CD player in it).

I should really check my old CDs/DVDs that I've got physical game patches/updates copied over to...they're getting long in the tooth. I may want to copy some old physical games as well.....guess I'll have something to keep me busy over the next few months!
 

p51d007

Posts: 2,442   +1,710
I have shot thousands upon thousands of photographs. I keep backups on my home PC NAS, my work laptop NAS, and two cloud sources. Guess I'm paranoid.
 
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Ludak021

Posts: 217   +146
Good. I am keeping some 50 discs and not throwing them away because I am afraid someone might use them. Burning them is obviously difficult in the city, and I am also too lazy to mess with all that dust. I guess now I can just throw them away!
Great read!
 

kiwigraeme

Posts: 43   +15
When I was just a pup ( well young dog ) and started ripping 2nd hand CDs - if wasn't all perfect and the internet wasn't so big . Sadly it took me a few years to realize - the reader makes a HUGE difference . Likewise when you burn DVDs- the burner and media made a HUGE difference - if you had your software telling you it was a perfect copy - no good unless testing on a couple of readers .
As for media - Recorded Music Cassettes were of trash quality . If you had a good recorder and media - the dynamics & background noise was much darker - plus they were much smoother in players - no shredding , tightening etc - if travelling your C120s played better than the stores C90s. Same Recorded VHS tapes from video stores were crap- I got a cheap chinese dvd player - press some key combo on the remote - hey presto no drm protection - My VHS tapes looked so much better than the rental ones
 

amghwk

Posts: 736   +511
So far all my DOS CD games all still working fine. More than 25 years old, I guess. Among my collection of DOS games CDs, the King's Quest V CD, early Windows 3.1x based "multimedia" CDs, etc..
 
Typically overstated and click-baity

First, if those disks were "backups" to begin with, then you've still got the masters, right?

Second, if they were "verified" when written, the failure rate today will be very small - about one per thousand disks.

I know because I have transferred thousands of CD-Rs and DVD-Rs between 10 and 20 years old.

==> AND they were all verified when written.

==> That's crucial to know because failures at write (verification) far outnumber failures due to aging. By at least 10:1. So failure rates reported now on non-verified or unknown disks mean almost nothing.

Yes, if you have priceless stuff on a single CD you'd better do something. Start by hoping that you verified the write. If you did, there's a 99.9% chance that you're still OK.
 

Steveb8189

Posts: 57   +43
I think the issue is with "burned" CDs not manufactured ones, I've never heard of Manufactured CD/DVDs going bad....only scratched :-/
That's because there are none that are over 40 years old. This quote is about manufactered CDs

"The test population selected for this experiment was extremely diverse; representing discs constructed using different materials, from different manufacturers and record labels. Although the selected discs covered a relatively limited period of manufacture the wide distribution of life expectancies demonstrates the effect of these varied construction parameters on disc life. 10% of the discs failed at an estimated life of less than 25 years, including 6 discs (5%) that failed too early to obtain meaningful data or a meaningful lifetime estimate. 23 discs (16%) had insufficient increase in errors during the test, and thus, had infinite lifetimes, by the standards of the ISO test method. These results illustrate why it is so difficult to make broad generalizations about the lifetime of optical media."
 
Taiyo Yuden master DVD-R are the best you can buy, have not had one issue with these even after reading data back after 18 years. Before the TY's I used the TDK DVD-R and DVD+R discs and these lasted less than 1 year before errors.

For your home movie transfers from analog tape to DVD the Taiyo Yuden DVD-R are also the safest option, they are expected to last at least 100 years!
 
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MaxSmarties

Posts: 269   +136
I'm still debated about backup strategy. I'm mostly relying on cloud based services like OneDrive and icloud, but I don't really feel safe especially regarding my photo library.
 

QuantumPhysics

Posts: 3,044   +2,860
SSD's read/write speed as well as their transfer speeds to and from other SSD is far faster than HDD.

As SSD gets cheaper, more people will move all of their Data to SSD simply so they can have access to 100% of it and have the benefits of solid state data storage.

The only reason SSD is not preferred for data archival right now is because of the high cost of SSD per gigabyte when compared to HDD.

as time goes on, cost is reducing, capacity is increasing and so is endurance.
 

BSim500

Posts: 684   +1,405
The only reason SSD is not preferred for data archival right now is because of the high cost of SSD per gigabyte when compared to HDD.
That isn't the "only" reason. Flash based storage weakness is unpowered data retention vs voltage drift. If you use an SSD as a system drive powered daily, there's no visible problem because the controller does periodic refresh of stale data in the background so that cell leakage / voltage drift never becomes an issue. However, when used as external backup / cold storage (which is how people use optical), it's a huge problem to write all your data onto a 8TB SSD, and throw it in the cupboard for 2 years. I've seen people do that with even TLC SSD's & flash drives and upon taking it out the whole lot was gone - not just the data but the file system and partition information too. People just naturally overwhelming use SSD's as system drives to the point where they then get lulled into a false sense of security in assuming unpowered vs powered will be the same as HDD's / ODD's whereas flash can be chronically unreliable for long-term unpowered backups.

Take a look at this Samsung 850 EVO chart to see what happens to read speeds after 48 weeks being unpowered (link) down from 550MB/s to as little as 15MB/s as the drive has to "guestimate" back the data it read. Far slower than a mechanical HDD due to extreme error correction needed. Now continue the downward trend of that chart for another 6-12 months until it passes the threshold where even the strongest LDPC ECC fails and the data gets permanently corrupted. That's why SSD's are cr*p for long-term cold storage backups and no real "replacement" for optical or HDD's.

as time goes on, cost is reducing, capacity is increasing and so is endurance.
Endurance isn't going up regarding SLC (100,000 P/E cycles) to MLC (10,000 P/E cycles) to QLC (as little as 300 P/E cycles), they're just lowering the overhead and measuring it differently. Eg, 1TB Samsung = 600TBW (860 TLC EVO) vs 360TBW (860 QLC QVO). But those "600TBW" for 1TB discs MLC could last 12x (and TLC could last 3-5x that) their official rating in actual endurance tests, but now we're seeing "360TBW" that barely last the rated 350-500TBW for QVO's.

The ultimate "red flag litmus test" is the warranty being reduced from 5 (TLC) to 3 (QLC) years on the same family of drives (already down from 10 year on MLC 850 PRO's). And endurance for backup (non system) SSD's is more than just P/E cycles, it includes unpowered data retention which very definitely isn't going up as cell sizes get smaller. Tech sites that should be doing real-world testing for this stuff, are sadly continuing to do little more than copy-paste figures from the marketing brochures.

As for the article, good intention but extremely weak "information". Zero information of HTL (inorganic) lasting 100x longer than vs LTH (organic dye) BD-R's. Zero mention of M-Discs. "Backup to a flash drive" is a purely short-term transitory measure, flash sure as hell isn't a "replacement backup" for any medium that can store data for years / decades in an unpowered state.
 
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QuantumPhysics

Posts: 3,044   +2,860
Who exactly is writing all their data to an SSD and throwing it into a cupboard?

The whole point of getting all of your old personal data onto a single SSD is to be able to access it at any given time. I wouldn’t be “storing” anything. I’d have an 8 TB SSD in my laptop and an 8 TB SSD in my desktop and using cloud services I’d be able to migrate data from one place to the next. I have no intentions of putting one of these things away for any length of time.


it’s a huge problem to write all your data onto a 8TB SSD, and throw it in the cupboard for 2 years.
 

BSim500

Posts: 684   +1,405
Who exactly is writing all their data to an SSD and throwing it into a cupboard? The whole point of getting all of your old personal data onto a single SSD is to be able to access it at any given time.
You seem to be projecting your own needs onto the market as a whole. People don't use cold storage / archival as an alternative for a NAS (if they want NAS-like capability they'll obviously just buy a NAS), they use it because they need to keep data offline (sometimes required in security audits for critical legal documents) as an alternative to, eg, commercial tape drive stored in fire-proof safes, etc. And the sad truth is there is still no real technological replacement for that. People who need this don't go around saying "Gosh, I think I'll buy 320x BD-R's as an alternative to an 8TB NAS for around-the-home media streaming", they simply have different more archival focussed needs for "WORM" like data from why people want an always on media streaming NAS.

I have no intentions of putting one of these things away for any length of time.
Optical is entirely about secure offline archival. If you don't need to archive anything offline, then clearly you're not the target market.
 
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amghwk

Posts: 736   +511
Archiving on SSDs? I wouldn't think that as wise. Unless someone wants to boast they have a 4 or 8TB SSD. Anyone can own a high capacity SSD, but owning one doesn't have to be a bragging right.
 

QuantumPhysics

Posts: 3,044   +2,860
You were talking about using a single SSD. My point was to at least copy that to an HDD. BSim500 explained why. But with all this pushback - forget it.
I have a NAS in my house. I always backup my personal documents and data, but since I'm only getting this for my OS and STEAM games - and all that stuff is redownloadable in the cloud, it's not that serious.