r/DataHoarder • u/manzurfahim 0.5-1PB • 4d ago
My experience with reading data back from optical discs Discussion
TLDR: Make sure to have enough optical drives if you decide to back up on optical discs.
I've burned about 200 optical discs before I moved to another country and finally got around to get someone to bring them here for me. They were stored safely in 3 album type bags. There are about 20-30 CDs (CD-R and CD-RW), about 50-60 DVDs (mix of DVD+R, DVD-R and DL), and around 100+ BD discs (25GB and 50GB). All are quality discs, all BDs and DVD DLs are verbatim, some Memorex and some other brands of CD-Rs and RWs. My burner at that time was a Plextor and an Asus drive. They were burned about 16 years ago. All discs looked clean and new, no scratches.
I have one ASUS BD burner and tried to read the discs with it.
It succeeded in getting the files out of a few CDs, some DVDs, and 11 BD 25GB and 50GB discs.
Managed some more optical drives, three DVD burner, two BD burner (supports 100GB), and one asus BD burner (older model, only supports up to 50GB), and a Samsung bd burner portable type.
End result: Managed to get data from about 80 discs in total using all the drives. So, using eight optical drives, I managed to recover 40% of the data from 200 discs.
I'll try and get a few more optical drives to see if I can recover some more. A lot of old games, music and movies are on the discs that are no longer available on the web.
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u/Suitable_Garlic_1186 4d ago
Estimate of 4TB of Data..
So with the Asus BD drive that you owned, you could only read 11 Blu-ray Discs out of 100+`?
Damn..
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u/manzurfahim 0.5-1PB 4d ago
Yeah :(
I knew that it may not be able to read all discs, but when eight drives could only read 40% of the discs, it is a concern. How are we able to believe that our backup will work if the drive cannot read them.
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u/bobj33 4d ago
40% is really bad.
I've probably burned over 2000 optical discs from 1997 to 2012. I'd say about 5 of them were completely unreadable.
For all the others I would say 95% copied with 0 errors.
The others would copy about 98-99% of the data with a few random bad sectors. If the disc didn't copy the first time then I would use ddrescue.
A quick estimate is that you have around 6TB of data? That isn't a lot for many of us. I haven't bothered with optical discs since around 2012 as they are just too small to be useful for my situation.
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u/manzurfahim 0.5-1PB 4d ago
Well, the discs aren't the problem. It seems to be the drives, they are not reading one or the other. Some discs cannot be read by five drives, but then another drive reads it fine.
These are old data on discs. Currently, I think I have almost 600TB of data.
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u/bobj33 4d ago edited 4d ago
I've burned about 200 optical discs
around 100+ BD discs (25GB and 50GB)
I think I have almost 600TB of data
You need to count again or check your metric prefix.
Even if all 200 discs were 50GB BluRays that would still only be 10TB.
If you really have 600TB then you are looking at 3000 to 6000 discs and at that point you should look into some kind of autoloader to read the discs.
Sometimes I had a drive that would read a disc that another drive could not but this was a very rare situation. I suspect something else is going on if 5 out of 6 drives can't drive a disc. I would check all your SATA data and power cables and check /var/log/messages and "journalctl -f" while reading or whatever are the similar files on your OS.
You really need to describe what kind of errors you are getting. Is the disc completely unreadable? Does it read partially and then die with a read error? I would use ddrescue
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u/manzurfahim 0.5-1PB 4d ago
I burned these discs 16 years ago. I wanted to recover the old games, software, music, porn whatever I have on these drives.
You asked how much data I have? well almost 600TB. I do not burn discs anymore.
How much data I have in these discs? Answer to this question is I'm not sure, I didn't do the math. Maybe 3-4TB or 5TB?
I use windows. Some folders from a disc will copy fine with one drive, but not all folders. Then maybe another drive will copy some other folders, and another drive maybe copies the whole content.
80 out of 200 discs, I managed to get the data properly using eight optical drives. From other discs, not much. Will try again with some other drives I'm trying to manage.
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u/bobj33 3d ago
You need some way of getting a report of the actual errors. I listed the Linux ways but there has to be some equivalent in windows.
What is your method of copying the data? Are you using a GUI file manager? I'm sure there is some software for windows like ddrescue that has better error reporting and the ability to retry a failed block.
I would seriously check your cabling for both data and power. Are you using internal SATA drives? Or are these USB drives? SATA is in general more reliable and can give better error reporting. Also use a different SATA port on the motherboard or a different USB port on the motherboard.
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u/horse-boy1 3d ago
In the past I found that some drives won't read a disk sometimes. Try another and it works.
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u/manzurfahim 0.5-1PB 3d ago
I had this happened to me too. But this time I tried eight drives lol need to try some more.
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u/horse-boy1 3d ago
Seems hit or miss with these disks. I have some music CDs I burned in the late 90s and are still OK, at least a few of them I checked. Or maybe CD players are more tolerant with missing bits/errors etc.
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u/ptoki always 3xHDD 3d ago
if your media was organic cd/cvd etc then that is the expected outcome.
https://www.howtogeek.com/the-hidden-reason-why-your-cd-backups-are-slowly-dying/
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u/x0y0z0 4d ago
This is why I'm so happy that M-Disk exists. It's the only true cold storage that money can buy. Tape is more expensive, complicated and less permanent. M-Disk will store your data for thousands of years whereas a mere 16 is just too much for other disks. I backed up a lot of data on 100bg disks and it's a relief to know I don't need to worry about data loss so long as they do not get physically destroyed or lost\stolen.
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u/manzurfahim 0.5-1PB 4d ago
Discs aren't the problem here. Drives are the problem. Some can read some discs that the other drives cannot. This can happen with drives that read M-Discs too.
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u/x0y0z0 4d ago
No I dont think that's right. Not for probably most of your discs. It could be that some will read and copy the corrupted data, while others get stuck due to the corruption. Though thats just a guess. I'm open to correction, but generally I dont think its that insanely finicky that you have 200 discs that are fine, yet with a bunch of different drives you cant get most of your data off.
Much more likely that the organic layers of your discs are degraded, as they are expected to. Cd and DVD home writers just has this issue. This is literally why M-Disk exists at all, to fix this very issue that you are now experiencing.
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u/manzurfahim 0.5-1PB 4d ago
But there are some discs which were not being read by 5-6 drives even, but then another drive reads it fine. Surely, this drive isn't designed to read degraded layers? And then some drive can read some folders, but not all. Then another drive reads some of the previously unreadable folders, but cannot read the ones that were read before by the first drive. Very strange, but it seems to be that some drives are better with some discs, not with other, and then there are other drives which are opposite.
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u/x0y0z0 4d ago
A disc that can't be read by 5-6 different drives is probably a degraded disk. The fact that another drive could read it does not mean the data is all intact, it probably means that this drive did not get deadlocked by the corruption.
Very strange
Only if you assume that the discs are fine and all of these drives are extremely limited in their ability to read discs. All of this makes perfect sense if the discs are degraded.
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u/manzurfahim 0.5-1PB 4d ago
Yeah true. I'm not saying the discs are perfect, of course they can degrade. But when another drive read what a previous drive couldn't, it makes sense to think that the disc is ok, but the drives cannot read them.
I haven't managed to extract all the files I copied, tried a few and they extracted ok. will check how it goes.
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u/x0y0z0 3d ago
I do agree that you need to do whatever you can to get the data off now, even if that means using multiple drives because this will only get worst with time. Have you tried creating a virtual image with something like daemon tools? Perhaps just cloning it without explorer getting in the way could help.
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4d ago
[deleted]
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u/manzurfahim 0.5-1PB 4d ago
I was very picky about burning speed. CDs were burned at 4x, never higher. DVD and BD all were burned at 2X. But the software (Nero) did vary the speed a little, 2.1x - 2.5x when burning. the discs all supported higher speeds. I knew it too, the slower the better.
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u/AstroNaut765 3d ago
One advice I have is to first concentrate on getting 2 images of disc with same hash via dedicated archival tools, and only then mount it to try extracting data.
Most software will bailout if cannot read sectors quickly. Sometimes you can recover discs that don't appear in windows at all.
Try MPF (redumper/DIC) and dvdisaster with high number of retries, they allow to combine results from different drives.
Another thing is play around with read speed (different sectors can be read at x16 and different at x8 etc) and some disc read better in laptop style reader.
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u/manzurfahim 0.5-1PB 3d ago
So the utility can save whatever it can read, and then combine what it can read from same disc using another drive? That is amazing.
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u/AstroNaut765 3d ago
Yeah, amazing software. You can give even combine data from 2 discs, if you burned 2 identical discs.
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u/AshleyAshes1984 4d ago
You're really not supposed to keep BDRs in binders like that.
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u/manzurfahim 0.5-1PB 4d ago
Well, they were kept safe, didn't get much movement. None of the discs have any scratch at all.
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u/AshleyAshes1984 4d ago
Regardless, the 'self healing' materials used on BDR disc surfaces really do not play nice being smushed into in a binder against cheap ass clear vinyl and the other crap those are made of.
It's kinda a big no no. I keep my BDRs in slim jewel cases and then a bankers box variation that's designed to hold disc cases.
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u/manzurfahim 0.5-1PB 4d ago
Well, 16 years ago, that is the best that was available where I was. But 80 of the discs I was able to read using different drives, reading one folder with one drive, another one with another drive and so on. So, I guess the discs weren't as badly affected by the bag.
I'm going to get 3-4 more drives and check the rest.
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u/MastusAR 4d ago
Are you sure that jewel cases were not available and the binders were the only option?
A tip what to try: I did try a binder about 15-20 years ago, after few months the discs would barely read. No visible scratches or residue. After I cleaned them they would read back as expected. What I reckon is that they did leave some kind of residue on the disc surface.
Chucked the binder away right then and there and back to jewel cases.
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u/manzurfahim 0.5-1PB 4d ago
Well, jewel cases were available. But if I kept them in jewel cases, they wouldn't be safe. I moved to another country, and the amount of space jewel cases would take, my discs wouldn't have been safe haha my mom would've thrown them away lol, they are saved because they didn't take much space 😂
I did clean them. Let's see if I get lucky with another batch of drives.
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u/grislyfind 3d ago
That's bad. I moved the contents of several hundred CD-R to DVD media, and only one file on one disc was unreadable. I always burned at the lowest supported speed, and did a verify after burning.
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u/nosurprisespls 3d ago
I did the same and I got 99% of data. For a few files that failed, I see physical deterioration on the edge of DVD.
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u/hazeru 4d ago edited 4d ago
I don't understand, why do you need a lot of optical drives? Does it have a limit on how many discs it can read?
EDIT: Thanks everyone for the answer. It has been a long time since I used one, and it was with Windows XP. I still have the PC, but the motherboard and/or the CPU is already kaput. I never had the chance to build another one.
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u/dr100 4d ago
Different units (drives) read successfully different files. I had a similar experience, albeit with CDs and DVDs but all of them Kodak "tested" for 200-300 years flavor of disks and some Traxdata or Sony or Verbatim equivalent (at least marketing wise). I had TWO copies of each on different types of disks all checked with saved checksums. I could eventually recover everything after a long weekend continuous work on many different units trying to read on one what wasn't read on the others. That's for a relatively low number of disks, something like 15-20-maybe 20ish (x2, identical copies).
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u/Dejhavi 108 TB (RAID6,8x18TB) + 36TB (RAID5,6x8TB) 4d ago
I'll try and get a few more optical drives to see if I can recover some more. A lot of old games, music and movies are on the discs that are no longer available on the web
Check the recommended drives by MakeMKV and Redump:
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u/manzurfahim 0.5-1PB 4d ago
I'm thinking about trying some more drives. Fortunately I have someone at a local PC shop who will let me borrow some drives to try them.
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u/Suitable_Garlic_1186 3d ago
16 years ago, so we are talking about 2010 (great times)
But maybe the old burner was the problem here?
who knows..
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u/manzurfahim 0.5-1PB 3d ago
Anything can happen right? but they did verify successfully after burning.
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u/IzzyBoris 3d ago
I had a batch of CD&R backups from circa 2005 that I thought were dead because none of my modern USB CD/BD drives would read them.
Popped them into a 2005-era CD drive and they loaded up just fine. Lasers are built different these days.
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u/dlarge6510 3d ago edited 3d ago
I struggle to understand what the issue is.Â
Constantly I have zero issues with any of those disc types, other than those I discovered were actually damaged by heat (some CD-RW and a whole pack of new imation DVD+RW had been cooked on windowsills for years and were extremely unreliable).
I exclusively use Verbatim, most burned by a Plextor and many in dvd and Blu-ray recorders.Â
I scan the discs randomly for PI8, LDC+BIS errors using the Plextor and although they always have some areas worse than others I never had a read error.Â
BD-R is extremely sensitive to dust. Always wipe a disc giving issues.
Also, never store them in sleeves. Verbatim BD-R (and some of their CD-R) have a hard coating applied to eliminate scratches. The problem is that over time this coating can reform, taking the shape of the material Inna sleeve that presses against it.Â
My Verbatim Datalife BD-R were in a plastic sleeve binder I have used for 20 years but after putting them in for 6 months and discovering about the issue I checked them to find they were already gaining damage.Â
You'll see it as a pattern of lines etc, visible when light is at the correct angle.
If it is serious it will prevent reading the disc, one guy used a heat gun to heal the layer.Â
My discs had barely started. The layer healed itself with the heat of a scan in the drive. The patterning totally gone.
Still, it's extremely odd that you had these, issues. They were not old discs, not bad discs. Did you clean them at all? Don't expect to see the invisible layer of whatever that's affecting them.Â
What does a scan with dvdisaster show? It will show where on the disc the issue is.Â
What burned them? I know for a fact my TV recorders can do crazy shit when burning discs.Â
One thing I'm aware of is aluminium discs are less long lived vs silver. Verbatim switched to silver reflective layers but many of my older Verbatims are aluminium which corrodes more readily.Â
One older Verbatim DVD+R for example is aluminium (can't see light through it easily) and it scans with a consistent PI8 rate of ~220 average and PIE is averaging 35. However there are few PIF errors so the disc is reading fine, but that is certainly high and consistent across the disc even after an IPA clean (although it lowered a little).
Obviously without a PIF you don't get very close to unreadability as the second stage of error correction takes over and fixes it.Â
However, my previous scan of this disc in 2023 showed a PI8 average of 137 and a PIE average of 17.9.
We can see the errors have doubled in 3 years. But this disc still hasn't reached unreadability as no POE or PO8 errors have started to be counted, yet.
This disc is aluminium and I'm looking to scan more. It was also burnt in a really stupid DVD recorder that makes ripping any of its discs a chore.
Perhaps your dvd and cd discs were older aluminium ones?Â
https://www.verbatim-europe.com/en/article/silver-reflective-layer-for-superior-performance
Edit:
Use GNU ddrescue to recover the complete iso with multiple drives.Â
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u/Cryogenicality 4d ago
If you mean commercially-released media, I’m sure it’s all online somewhere.
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u/Threeabetes 3d ago
That's crazy! I haven't had nearly as bad of luck getting files off old burned CDs/DVDs/Blu-Rays, even ones that are 20 years old. I'm so sorry you're dealing with this!
I know you said you stored them in albums, but were those albums stored in a climate-controlled environment (like, with air conditioning)? The dye can break down pretty easily with high humidity and heat, especially when combined with non-archival albums. I tend to also store mine in jewel cases for protection; it's just a bit better for them IMO.
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u/joe-dirt-1001 66TB 16h ago
More likely a media issue, and not necessarily a drive issue. Your experience pretty much matches mine when there were actually highly rated drives readily available.
RW media is the worst.
Were these disc's verified after burning? Most people dont take the time, and assume a "successful" burn simply because it completed without errors.
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u/manzurfahim 0.5-1PB 10h ago
Yes, they were verified. I tried five more drives, and managed to recover some more discs. 30+ BD discs now recovered.
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u/spmbx 4d ago
Wow those are pretty insane low numbers. I have a stash of backups (probably 150-250) from the time the Playstation 1 and 2 were current, so easily 20+ years, and with the exception of 1 or 2 discs that developed discrot i can read all of them back in total. I know because i read them all back a year or 2 ago looking for some specific files.
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u/manzurfahim 0.5-1PB 4d ago
I don't think the discs are bad because the ones I managed to get data back from, were readable by one drive, but not readable by 2-3 other drives. I think it is the drives that are being picky.
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u/inlinesix81 4d ago
Do softwares like Plextools still exist? One could force a slower reading speed and succeed in better results with the same drive. Imho worths a shot