How to prevent cyclic redundancy errors ??

[contactadam2002]

I used winRAR to split large video files into sizes that could fit onto DVD+R and DVD+R DL discs. Since this was being done across nearly 100 discs, I got the data cyclic redundancy error on atleast one of them. If I have the burning software verify the disc after completion, then does this mean that it'll be able to confirm if there is a data cyclic redundancy error.
They're being kept in a DVD case storage for backup so there's no chance of the cyclic redundancy errors occurring after burning. If it happens, then it's because it wasn't burnt properly. So does verifying guarantee that this won't be an issue?

[jeffy]

No, the media might degrade in the course of time.

You might consider using something like free dvdisaster (at the expense of additional storage):
http://dvdisaster.net/en/index30.php

[fibbingbear]

Like Jeffy said, errors can creep in over time --- the DVDs will degrade over time, and bits will be harder for the laser to read and eventually be read incorrectly.

The same problem happens with hard drives, basically any storage medium.

The ways around this are usually through redundancy. If you have multiple copies, and can confirm that a disc went bad, you can pull up a copy of the disc. I keep my stuff on my hard drive and have 2 backup drives.

Stuff like DVDisaster, as mentioned above, take less space than a full, redundant copy, but have the disadvantage that they only work if a small part of the data is corrupted and the rest is fine. So keep in mind that if a lot of the disc becomes corrupted, DVDisaster won't help. I have no idea how DVDs degrade over time, and if this makes more sense than multiple copies (which will take up more space).

Don't forget a CRC is not foolproof. It could be possible that the disc is corrupt but the CRC won't detect this. However, this is extremely unlikely (less than 0.0001% chance of happening, or something in that ballpark).

I personally use secure hashes, since they have even lower error rates, like 0.000000000000000000001%. Not that I recommend doing that unless you like programming, since I haven't seen a lot of ripping programs that support SHA/RIPEMD/other secure algorithms.

[contactadam2002]

Damn it, it turns out that although my two DVD drives failed to read it, the one on another computer could with no problems.

The fullproof storage medium that will survive time and never goes wrong are flash drives, which are increasing steadily in size. No moving parts and no dodgy layers or lasers.
SSD drives are probably almost as good.

[kumi]

The fullproof storage medium that will survive time and never goes wrong are flash drives.
That is absolutely false. SSD MTBF figures are still far worse than conventional spinning-disc drives. Wear-levelling and experimental new error-correction techniques (http://blog.enterprisestoragesense.com/) can help, but they're not there yet.

[Inventive Software]

I had CRC errors with a drive at uni only 10 hours ago, it just wouldn't read DVD+RWs properly, it was always temperamental, and until I got home and used the one on my laptop, I couldn't tell whether it was a bad burn or the drive's fault. The disc was perfect, just the drive being pissy.

[rebkell]

I'd recommend quickpar, it will create parity files and you can recover corrupted files, if you're just storing them, par will split the file up into chunks of any size you like and it will create the parity files to repair any corrupted files you have. It takes a bit longer to generate the parity files, but unless you have just a total disk failure, it will more than likely be able to restore the original.

[contactadam2002]

Ok KUMI you make a fair point about SSD, but you can't fault flash devices such as SD cards or usb sticks. I've used them time after time and have never experienced or heard of problems. No moving parts, quick access, no laser or dodgy disc layers, shielded against electrical interference, fairly resistant to scratches, heat and to a point water. I'll happily trade all my HD's in for the supposed 1TB flash drives that are alleged to be in the prototype stages according to technology review. If anyone disagrees do tell, I don't want my faith to be misplaced.

[Irakli]

Ok KUMI you make a fair point about SSD, but you can't fault flash devices such as SD cards or usb sticks. I've used them time after time and have never experienced or heard of problems. No moving parts, quick access, no laser or dodgy disc layers, shielded against electrical interference, fairly resistant to scratches, heat and to a point water. I'll happily trade all my HD's in for the supposed 1TB flash drives that are alleged to be in the prototype stages according to technology review. If anyone disagrees do tell, I don't want my faith to be misplaced.

I experienced some data corruption with SD card; even worse, there were no read error reports while copying files from card to hard drive, although most of the data on the card was actually corrupted. CD/DVD/Hard Drive will at least tell you if the data is corrupted and cannot be copied.

I have to admit that I had no issues with memory sticks though.

Regards,
Irakli

[mickeblue]

I hope you folks don't mind this subject being re-opened. I'm trying to make a back up of a brand new disc... watched only once on a Sony dvd player ( without any problems )... 39 seconds into backing it up using Shrink 3.2 I get a "failed to read the file "D:\" Data Error(C.R.C.)" message.

I've Googled the problem and read suggestions from cleaning the disc with everything from Arm & Hammer toothpaste to vodka with 3 ice cubes added :-) [ presumably to lessen the pain of failure ], but no real explanations of why this error occurs. It ain't the drive... I can work a copy either side of the problem... I've cleaned the disc with professional wipes... and it's a new disc. If anyone could offer me a real solution to what is going on here I might be able to figure ut a workaround.

Thanks in advance

[dialysis1]

Try DVDFab HD Decrypter.
http://www.dvdfab.com/free.htm

[smok3]

even worse, there were no read error reports while copying files from card to hard drive, although most of the data on the card was actually corrupted.

i had the usb HDD drive that behaved like that as well (for about 2 days that is), no errors reported by the system, only md5 mached maybe only like 4 of 5 times.