How to pinpoint errors on a data CD?

[nlec]

I'm refreshing my collection of old data CDs I've burned over the last several years. I'm consolidating the data files I backed up onto TY DVD+R blanks.

On one el cheapo CD-R I burned in January of 2003 I have almost 5,400 files in 1,800 directories consuming about 640 MB bytes. xcopy copied many files but choked on an error after a while. IsoBuster was able to create an iso image of the disc for me, but there were perhaps a dozen sector read errors where I told it to replace the bad sector data with 0s. I mounted the iso image on a virtual CD-ROM drive in XP SP2 and xcopy from that to the hard disk ran without any errors.

Most of the data is fine. There are html, MS Word, and PDFs that are OK. But I know there are some files that will not be OK because of the sector errors on the CD. I ran into one PDF that would not open and a BMP that Photoshop refused to load. There are undoubtedly other files that are bad.

Is there a tool that will tell me which files were located at specific sector numbers on the CD? Is that information available from the TOC on the disc? If there is I can match the bad sector numbers given to me by IsoBuster and see exactly what I have lost.

[SanderMan]

You can use cdcheck for that. download at http://www.kvipu.com/CDCheck/

[jman98]

While this is a little beyond the scope of your specific question, if you're backing up a lot of things and want to be sure you have good copies, you might look into making and storing separate PAR files for your backup discs. You could set up PAR files to let you recover if 5% or 10% (or more if you wish, but it produces bigger files) of your archive is damaged. I read here on these forums about a guy who backups stuff to DVD or CD (I forgot which) and he stores PAR files on another disc to enable him to recover the archive if it gets corrupted. You might want to look into this.

[EddyH]

I don't want to come across as too much of a gimp for Ahead software too often, but I'd use Nero CD/DVDSpeed (again ) if you have access to it. There's a handy tab where you can run what is basically a version of Scandisc for optical media... once it's done (assuming it doesn't hang at a bad section ) you'll have a list of files and a judgement on whether they're "good" (read ok first time), "damaged" (read ok eventually, but needed retries), or "bad" (could not be successfully read for some/all of their length). Makes it simple.... you know which ones to get off there immediately at high speed before any other disaster strikes (good), which to get next, letting the drive churn for a while at a slightly lower speed (damaged), and which to break out the big recovery guns for - whitening toothpaste, olive oil, 1x speed, etc! (bad)

Signed, the victim of rubbish, corroding early-days CDR / RW media

[nlec]

Thanks for the tips. I'm going to give cdcheck and CD/DVD Speed a try this evening.

I ran into another disc today I burned in 2003 with similar problems. It read 98.5% fine and then started giving read errors. FWIW I have always used whatever "verify after burn" options were available in my burning software, so I am confident the burns were good 4.5 years ago. I should mention there are 6 other discs from the same batch that were readable without any errors at all.

It is scary taking literally tens of thousands of files and trusting them to 1 blank DVD. Too bad there's not a filesystem format for burning that saves redundant error-correcting data natively (like PAR files do) as part of the burn.

[Delerious]

Have you checked out dvdisaster yet?

[nlec]

No, but I will since neither Nero nor cdcheck did what I wanted. They go until they encounter a read error, tell me about the file that couldn't be read, and stop. I'd like to know all the files that cannot be read, not just the first one.

I still have the CDs that were giving me trouble. At some point I will toss them and that time is drawing near, so thanks for another suggestion.

UPDATE: While it looks like it might be useful as a preventive measure when you burn new discs, it doesn't do anything new for me except draw a pretty picture. I uninstalled it already.

[fatbloke88]

hi try"Dead Disk Doctor" on the cd disk , its got back files that isobuster failed on for me

[guvidal]

This might be too late, but your solution is http://www.imgburn.com/
Use Verify Mode, it'll give you all the bad sectors (not just the first one) and will let you know which file is affected by it.

[Cornucopia]

Did you try ISOBuster's "Managed" Images (which allows one to use the best rips from multiple drives)? This has greatly improved rips from badly damaged discs for me. IIRC, it is only available to "Pro" use, so you would have to register (read $), but it's worth it.

In the meantime, one should ALWAYS verify disc burns for important stuff you're archiving--especially for CD-Rs where you're really not losing any time with such high burn/read speeds.

Scott

[AlanHK]

Did you try ISOBuster's "Managed" Images (which allows one to use the best rips from multiple drives)?

Isopuzzle has a similar feature, and it's free.