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I have a very strange case of DVD reading failure.

It's a video DVD recorded a couple of years ago on a DVD-R disc.

Two weeks ago our video DVD player would start having trouble reading parts of it. The problem was reproducible on two PCs, where only part of the videos could be played. Plus, current playing time and total duration of VOB files would me messed up, indicating that the files were corrupted somehow, likely due to disc aging.

Three days later, I wanted to play the same videos again (same setup, same laptop DVD reader) but I couldn't even view the DVD's file structure. To avoid further losses, I launched

$ ddrescue -n -b 2048 /dev/sr0 ~/dvd_dump

After six hours and since I needed to shutdown my laptop, I interrupted the process and decided I would restart it later.

However, two days later, the DVD reader would not even recognize the presence of a disc, throwing a no medium found error whenever I tried. Also the disc would not start spinning upon closing the tray.

This situation was reproducible on three different DVD readers.

Some details:

$ dmesg | grep sr
[    3.078673] sr 3:0:0:0: [sr0] scsi3-mmc drive: 52x/52x writer dvd-ram cd/rw xa/form2 cdda tray
[    3.078891] sr 3:0:0:0: Attached scsi CD-ROM sr0
[    3.078960] sr 3:0:0:0: Attached scsi generic sg4 type 5

$ lsblk
NAME   MAJ:MIN RM   SIZE RO TYPE MOUNTPOINT
sda      8:0    0 931,5G  0 disk 
├─sda1   8:1    0   100M  0 part 
├─sda2   8:2    0 597,5G  0 part /mnt/win
├─sda3   8:3    0     1K  0 part 
├─sda4   8:4    0     1G  0 part 
├─sda5   8:5    0 323,2G  0 part /
└─sda6   8:6    0   9,8G  0 part [SWAP]
sde      8:64   0   1,8T  0 disk 
├─sde1   8:65   0     1K  0 part 
├─sde5   8:69   0 398,7G  0 part 
├─sde6   8:70   0 951,8G  0 part 
└─sde7   8:71   0 512,5G  0 part 
sr0     11:0    1  1024M  0 rom  

$ cd-info --dvd
cd-info version 0.83 x86_64-pc-linux-gnu
Copyright (c) 2003, 2004, 2005, 2007, 2008, 2011 R. Bernstein
This is free software; see the source for copying conditions.
There is NO warranty; not even for MERCHANTABILITY or FITNESS FOR A
PARTICULAR PURPOSE.
CD location   : /dev/cdrom
CD driver name: GNU/Linux
   access mode: IOCTL

Vendor                      : TSSTcorp
Model                       : CDDVDW SH-S223C 
Revision                    : ME00
Hardware                                  : CD-ROM or DVD
Can eject                                 : Yes
Can close tray                            : Yes
Can disable manual eject                  : Yes
Can select juke-box disc                  : No

Can set drive speed                       : No
Can read multiple sessions (e.g. PhotoCD) : Yes
Can hard reset device                     : Yes

Reading....
  Can read Mode 2 Form 1                  : Yes
  Can read Mode 2 Form 2                  : Yes
  Can read (S)VCD (i.e. Mode 2 Form 1/2)  : Yes
  Can read C2 Errors                      : Yes
  Can read IRSC                           : Yes
  Can read Media Channel Number (or UPC)  : Yes
  Can play audio                          : Yes
  Can read CD-DA                          : Yes
  Can read CD-R                           : Yes
  Can read CD-RW                          : Yes
  Can read DVD-ROM                        : Yes

Writing....
  Can write CD-RW                         : Yes
  Can write DVD-R                         : Yes
  Can write DVD-RAM                       : Yes
  Can write DVD-RW                        : No
  Can write DVD+RW                        : No
__________________________________

Disc mode is listed as: Error in getting information
++ WARN: error in ioctl CDROMREADTOCHDR: No medium found

cd-info: Can't get first track number. I give up.

$ sudo mount -t iso9660 /dev/sr0 /mnt/dvd
mount: block device /dev/sr0 is write-protected, mounting read-only
mount: no medium found on /dev/sr0

I am very surprised to see a DVD going from large parts still readable to totally undetectable within a week. I treated the DVD with maximal care, did not carry it around anywhere, and no physical damage (scratches or the like) were visible before, nor are there any now.

My questions:

  1. Is there a way to force-read the disc with a low-level command that would ignore the no medium found error, or cd-info's Can't get first track number error (see above)?
  2. Is it plausible that a faulty DVD reader would overwrite the DVD-R with zeros when it was only supposed to read-access it via the ddrescue command quoted above?
  3. What options do I have left? Is there any chance that professional data rescuing services will be capable of salvaging my disc?
  4. Are there high-end DVD readers on the market with superior error-correcting capabilities that might extract something from that disc?

(Before someone asks: Yes, I am sure it was one and the same disc!)

Edit: The disc is a TDK DVD-R Data/Video 4.7 GB 1-8x.

DVD readers (from cd-info output):

  • TSSTcorp CDDVDW SH-S223C Revision ME00 (3.5-inch drive on desktop PC at workplace, age unknown)
  • MATSHITA DVD-RAM UJ-844 Revision RC06 (on Lenovo Thinkpad X301, ~8 years old)
  • unknown (I will edit this once I get the info)
6

Initial Disk Quality

Since we're not talking about a hard drive here, which can be recovered, you're sadly experiencing the reality that most consumer grade DVDs are NOT reliable.

A physical hard disk has magnetic charged particles in a solid surface, and recovery in worst case scenarios happens by taking the disk apart physically, and then using a special read head to go sector by sector and reading the magnetic data. A dye based writable dvd has no such option, the dye is the data, and if it's degraded, there is nothing to recover.

The only likely prospect given your scenario is that the dye used to create DVD-R disk data simply is failing. Unlike commercial music CDs, which usually use a sort of laser enscribed aluminum sheet for the actual data, burnable dvds use a layer of dye, which, and this is particularly relevant with lower end stuff, tends to fade away and fail over years.

Note that 'cheaper' does not necessarily refer to price or brand, it refers to the factory that actually made the disks. Some major brands that people would have believed were high quality were not in fact high quality.

This is also, by the way, why you always have to buy name DVDs, like Taiyo Yuden (back when I did a lot of burning, that's the only brand I would use), or quality 'archival' dvds [which cost a LOT more than regular ones]. Cheaper dvds/cds use cheaper dyes, which can and do simply fail over time. The only brand I ever trusted was taiyo yuden, because it never outsourced its disk production and was known to be be high quality, and was made in Japan [this could have changed since I did a lot of work with CDs/DVDs]. If the disk was made by a no name or whitebox brand, then it's junk, for sure. I've seen dyes on CDs fade after just a few years when they were cheap no name brands.

You may have heard the term 'archival DVDs', this is what it refers to, the expected life of a properly stored optical storage medium.

Since you did not mention the brand of the disk, that suggests to me that you were not aware of these realities, since the key to all optical disk storage is the quality of the disk and its dyes, and that's a function of what brand and model version it is.

It's also worth mentioning that rewritable CD/DVDs are far far worse, and should in no case be relied on for really anything at all, at least that's been my experience, over years, I think the data loss become so high that I no longer even consider optical rewritable anything to be a storage medium at all.

How to Kill your DVD/CD

Things that can damage these dyes: heat, probably number one, like, putting disk on or near radiators, electronic components that generate heat, direct sunlight, etc.

Once you have damaged the dye there is no longer any data there to restore, and if you damaged the actual data table on the dvd itself that says where the data is, then there is nothing to restore either.

Other good ways to lose your data is to buy cheap or no name disks, that means you will wake up one day and find your data gone, without having to do a thing!! Just from the dye failing on its own, though I'm sure environmental causes can contribute, like the place it's stored getting a bit warmer for a few days in a row, or whatever.

Last Chances

Before you give up, you might want to try the following:

  • Take a clean soft cloth, dampen it slightly, and carefully wash the surface of the disk. In particular pay close attention to the inner, not outer part. The disks burn from the inside out, so if there is dirt or scratches there, it can make the reads fail.

  • Try it in a very high quality DVD reader, like a plextor, something with a very good laser. Lasers can and do wear out, and, coupled with dye fade and failure, that can make disks fail to read. Do not assume a DVD reader laser is in good condition, they die over the life the reader, so the newer it is, the better. As with dyes, there is a significant difference between the quality of the lasers used by CD/DVD readers/writers. The laser is what heated the dye when it was burned, and it's what tries to read it when it reads. The better the laser, the more likely it can pick up faint traces of fading dyes.

  • take a magnifier and closely examine the disk under strong light close to the inside rings, to see if you can see anything unusual there, like cloudy surface, or something like that. This is what it has to read to discover that there is a disk with data present.

  • laptop dvd drives are junk, cheap, low end, flimsy, lightweight, I wouldn't even consider them to be a valid test, make sure to use a real PC dvd reader, that is not too used or old, or cheap.

  • The device you listed: http://www.driverscape.com/download/tsstcorp-cddvdw-sh-s223c-ata-device appears to be over 10 years old, is that correct? If so, that's clearly not going to be a good tool to test this with.

Back in the old days, you could actually rely on the fact that certain brands and models had superior lasers, but in my opinion, those days are sadly gone. But if you research it, you may find that there are still certain specific models that are known to have a superior laser, obviously, I would expect those to be higher end and expensive.

Note that the age of the reader is also important, because these lasers basically begin to die as soon as they are used, so the newer the high end reader is, the higher your chances at recovery.

However, with that said, the marked decline in reading over a short time suggests to me that something started breaking down the DVD dyes, until it failed, possibly an inadvertent leaving it in direct sun or on a hot surface, without you having realized it, or simply the dye itself breaking down because it was either cheap or defective in the first place.

Likewise the drives not finding any data suggests the file system data table in the start of the dvd is either gone or corrupted beyond repair or read.

[Update: user data added to post]

As I suspected, you used no name dvd blanks, which are basically guaranteed to be non trustworthy, and your dvd readers are old. Old burners by the way can also have weaker lasers, which makes the dye imprint weaker, so it looks like you're suffering from all the worst case scenarios.

Where to get good disks?

I haven't bought these in a while, but to make this complete, I searched, and was very happy to find that supermediastore.com still exists, and still sells Taiyo Yuden. https://www.supermediastore.com/products/jvc-taiyo-yuden-dvd-r-8x-silver-thermal-dvd-recordable-single-layer-media-jdmr-zz-sb8-100pk

This was the best place to buy 10-15 years ago, and it appears to still be around, which is great, I always trusted that store and their products, which is an unusual thing to be able to say nowadays.

Note that other good archival options are things like Verbatim DataLifePlus, but in general, I only stick with brands where I know that the brand is actually made by the company whose brand the disks carry.

But the key thing to remember is: if the data on the disk is important, PAY FOR QUALITY DISKS!!

  • Does read-accessing the DVD contribute to its wearing out, especially if the disc is in such critical state? Should I make personal rescue attempts very sparingly, and go to a professional (with high-quality readers) before trying anything else? – jens Sep 8 '17 at 21:48
  • If you are going to get any data from this device, my guess is you have about max 1 full attempt left, if that much. The fact it's degrading as quickly as you claim suggests strongly the dyes have failed. Personally I don't see any point to paying someone to tell me that there is no data present, if I were in your shoes, I'd buy a good quality reader after researching it since that will be cheaper than data recovery, and I'd have the reader when it was done. But since it will only take the pro a few seconds to test if he can read it, that could be worth it, if the data is worth it. – Lizardx Sep 8 '17 at 21:52
  • I suggest you update your post with the following: brand and model of dvd readers you have tried, and how old they are, and how much used. Brand/model of dvd blank used to record the failing dvd. If it's a noname brand/model, then the data is probably gone. – Lizardx Sep 8 '17 at 21:56
  • I corrected the disc brand: it's a TDK, not a noname. Sorry. – jens Sep 9 '17 at 6:09
  • As I indicated, what actually mattered back when you bought the disk was who actually made it, not the brand printed on it. Back when I followed this stuff more closely, very few of the big brands actually produced their dvd/cd blanks themselves. However, since it seems fairly obvious the dyes are fading and becoming unreadable, that's not actually that important. Though I would try with a new quality dvd reader, not in a laptop, before giving up. Then I'd buy a stack of quality dvds and new dvd rw devices and go on from here, having learned a lesson we all learn, research, then get buy.. – Lizardx Sep 9 '17 at 6:17
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  1. Is there a way to force-read the disc with a low-level command that would ignore the no medium found error, [...] ?

Probably not. Such a message is usually triggered by error indications from the drive. You could possibly learn more from

dvd+rw-mediainfo /dev/sr0

when the DVD is inserted in the drive.

  1. Is it plausible that a faulty DVD reader would overwrite the DVD-R with zeros when it was only supposed to read-access it via the ddrescuei command quoted above?

Not plausible. You need a burn program to make the write preparations before drive and a DVD-R medium would accept WRITE commands. And this only on the yet unwritten part of the DVD-R. (The risk to overwrite is rather with DVD-RAM, DVD+RW, BD-RE, formatted DVD-RW.)

  1. What options do I have left? Is there any chance that professional data rescuing services will be capable of salvaging my disc?

Try with as many DVD drives as you can access. Try with cautious cleaning of the DVD. I have no experience with pricing and success of data rescue services.

  1. Are there high-end DVD readers on the market with superior error-correcting capabilities ... ?

It's not about the error correction (which all have) but rather the quality of the laser reflected signal.

Have a nice day:)

Thomas

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