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#1
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Trying to explain cause of CD corruption
Okay, here's the situation:
Say you have about 2200 source code files. Spread across a handful of subfolders and varying numbers of subfolders in each of those. They were burned to a CD, and when you do a visual compare in Windows Explorer between the files on the CD and the same files on a hard drive, they appear to be the same. Same filenames, same file sizes, modification dates/times. However, if you run a file compare (say windiff), you notice that about 2/3rds of the files are coming up different. Look in one of the subfolders. There are say 5 files: a.h (2k in size), b.h (16 kb), c.h (10 kb), etc. If you look at a file in the subfolder, say "a.h" (C language header file) and open it in a text editor, you discover it's really the text from "b.h". At least only the first 2kb of it. Open b.h and it's the rest of the b.h file (resuming exactly where the previous file left off), plus at the end, a bit of the top of c.h. It's like the bytes are all there, but "shifted" onto the next sector. The degree of "shifting" appears to be about 1680 bytes. The CD was probably created with Roxio CD Creator version 6 (yeah, an old version--it's what was installed on the PC). Don't have details on the CD drive manufacturer. Under Windows 2000 or XP (don't know for sure--the person that did the original burning is long gone from the company). Has anyone seen anything like this before? And if so, did you ever figure out a reason why? I remember a lifetime ago seeing similar issues on floppy disks when the FAT table would get scrambled, but never on a CD. I work in Compliance for a manufacturing company in a HIGHLY regulated industry and I've inherited this problem. I now have to explain how it happened to a (non-technical) regulator or the company faces potentially huge fines. The regulator isn't buying just "the CD was corrupted when it was created." Thanks in advance for any assistance. |
#2
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Trying to explain cause of CD corruption
I don't know if isobuster could help.
-- Ed Light Better World News TV Channel: http://realnews.com Bring the Troops Home: http://bringthemhomenow.org http://antiwar.com Iraq Veterans Against the War: http://ivaw.org http://couragetoresist.org Send spam to the FTC at Thanks, robots. |
#3
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Trying to explain cause of CD corruption
Ed Light wrote:
I don't know if isobuster could help. I'll check it out. I need to explain how it happened, not rescue the data--we have multiple copies of the data. I looked at the isobuster website and it looks like this product allows you to view a CD sector by sector. Maybe that will allow me to identify the exact sector where the problem occurred. Unfortunately I only have a copy of the CD to work from. I doubt the sectors are exactly the same. It would be best if I could discover the root cause, and be able to reliably duplicate the problem. Thanks for the input! |
#4
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Trying to explain cause of CD corruption
.. --------------------------------------
Mike Richter, were you born with "Scam Artist" emblazoned on your face? -------------------------------------- http://tinyurl.com/gqnae (No Mikey S-lickers have been able to prove ANY of the above ) (is a LIBEL -- despite Mikey claimed to have PROOF of libels!) ' anonymousNetUser wrote: Okay, here's the situation: Say you have about 2200 source code files. Spread across a handful of subfolders and varying numbers of subfolders in each of those. They were burned to a CD, and when you do a visual compare in Windows Explorer between the files on the CD and the same files on a hard drive, they appear to be the same. Same filenames, same file sizes, modification dates/times. However, if you run a file compare (say windiff), you notice that about 2/3rds of the files are coming up different. Look in one of the subfolders. There are say 5 files: a.h (2k in size), b.h (16 kb), c.h (10 kb), etc. If you look at a file in the subfolder, say "a.h" (C language header file) and open it in a text editor, you discover it's really the text from "b.h". At least only the first 2kb of it. Open b.h and it's the rest of the b.h file (resuming exactly where the previous file left off), plus at the end, a bit of the top of c.h. It's like the bytes are all there, but "shifted" onto the next sector. The degree of "shifting" appears to be about 1680 bytes. If that were 2048 bytes, I would guess that file pointers are off by a sector (never minding why and how). . The CD was probably created with Roxio CD Creator version 6 (yeah, an old version--it's what was installed on the PC). Don't have details on the CD drive manufacturer. Under Windows 2000 or XP (don't know for sure--the person that did the original burning is long gone from the company). Has anyone seen anything like this before? And if so, did you ever figure out a reason why? I remember a lifetime ago seeing similar issues on floppy disks when the FAT table would get scrambled, but never on a CD. I work in Compliance for a manufacturing company in a HIGHLY regulated industry and I've inherited this problem. I now have to explain how it happened to a (non-technical) regulator or the company faces potentially huge fines. The regulator isn't buying just "the CD was corrupted when it was created." Thanks in advance for any assistance. I would get Total Commander, a shareware file manager, and then (1) compare hard disk and cd side by side, (2) compare two files by content, (3) view a file, etc. (1) Commands menu Synchronize Dirs (2) Files menu Compare By Content (after right-click files to compare) (3) F3 View http://www.ghisler.com/ Also use IsoBuster to view cd sectors: Right-click, Sector View. This comes in handy to view Primary Volume Descriptor, directory entry, etc. http://www.isobuster.com/ Hope you get some more information with the above two to aid your investigation. |
#5
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Trying to explain cause of CD corruption
On Aug 1, 2:42*am, smh wrote:
. * * * * *-------------------------------------- * * * * * * * Mike Richter, were you born with * * * * * *"Scam Artist" emblazoned on your face? * * * * * *-------------------------------------- * * * * * * * * *http://tinyurl.com/gqnae *(No Mikey S-lickers have been able to prove ANY of the above ) *(is a LIBEL -- despite Mikey claimed to have PROOF of libels!) ' anonymousNetUser wrote: Okay, here's the situation: Say you have about 2200 source code files. Spread across a handful of subfolders and varying numbers of subfolders in each of those. They were burned to a CD, and when you do a visual compare in Windows Explorer between the files on the CD and the same files on a hard drive, they appear to be the same. Same filenames, same file sizes, modification dates/times. However, if you run a file compare (say windiff), you notice that about 2/3rds of the files are coming up different. Look in one of the subfolders. There are say 5 files: a.h (2k in size), b.h (16 kb), c.h (10 kb), etc. If you look at a file in the subfolder, say "a.h" (C language header file) and open it in a text editor, you discover it's really the text from "b.h". At least only the first 2kb of it. Open b.h and it's the rest of the b.h file (resuming exactly where the previous file left off), plus at the end, a bit of the top of c.h. It's like the bytes are all there, but "shifted" onto the next sector. The degree of "shifting" appears to be about 1680 bytes. If that were 2048 bytes, I would guess that file pointers are off by a sector (never minding why and how). . The CD was probably created with Roxio CD Creator version 6 (yeah, an old version--it's what was installed on the PC). Don't have details on the CD drive manufacturer. Under Windows 2000 or XP (don't know for sure--the person that did the original burning is long gone from the company). Has anyone seen anything like this before? And if so, did you ever figure out a reason why? I remember a lifetime ago seeing similar issues on floppy disks when the FAT table would get scrambled, but never on a CD. I work in Compliance for a manufacturing company in a HIGHLY regulated industry and I've inherited this problem. I now have to explain how it happened to a (non-technical) regulator or the company faces potentially huge fines. The regulator isn't buying just "the CD was corrupted when it was created." Thanks in advance for any assistance. I would get Total Commander, a shareware file manager, and then (1) compare hard disk and cd side by side, (2) compare two files by content, (3) view a file, etc. (1) Commands menu Synchronize Dirs (2) Files menu Compare By Content (after right-click files to compare) (3) F3 View http://www.ghisler.com/ Also use IsoBuster to view cd sectors: Right-click, Sector View. This comes in handy to view Primary Volume Descriptor, directory entry, etc.http://www.isobuster.com/ Hope you get some more information with the above two to aid your investigation.- Hide quoted text - - Show quoted text -- Hide quoted text - - Show quoted text - Is the disk a UDF or Joliet? If UDF, do very short files ( 1K) display correctly. Where the disks written in one session, or appended? Are the disk CD-R or CD-RW? Michael www.cnwrecovery.com |
#7
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Trying to explain cause of CD corruption
Don't know. The person that created the disc left the company and their PC has been reformatted and repurposed. The original disc is in the hands of the regulator and cannot be examined. We normally do only CD-R. That's about all I'm sure of. It should tell you in isobuster, or your writing program. -- Ed Light Better World News TV Channel: http://realnews.com Bring the Troops Home: http://bringthemhomenow.org http://antiwar.com Iraq Veterans Against the War: http://ivaw.org http://couragetoresist.org Send spam to the FTC at Thanks, robots. |
#8
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Trying to explain cause of CD corruption
Ed Light wrote:
Don't know. The person that created the disc left the company and their PC has been reformatted and repurposed. The original disc is in the hands of the regulator and cannot be examined. We normally do only CD-R. That's about all I'm sure of. It should tell you in isobuster, or your writing program. I played with ISOBuster all day today. Pretty cool program--and less then 5MB! Gotta love it when a programmer really knows what they're doing. I know I always burn CD-R, but I can't vouch for what the person that burned the original over a year ago did. And the copy the regulator sent us in on a CD-RW. |
#9
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Trying to explain cause of CD corruption
anonymousNetUser wrote:
I know I always burn CD-R, but I can't vouch for what the person that burned the original over a year ago did. And the copy the regulator sent us in on a CD-RW. I see -- there's no way to know about the original. -- Ed Light Better World News TV Channel: http://realnews.com Bring the Troops Home: http://bringthemhomenow.org http://antiwar.com Iraq Veterans Against the War: http://ivaw.org http://couragetoresist.org Send spam to the FTC at Thanks, robots. |
#10
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Trying to explain cause of CD corruption
Ed Light wrote:
anonymousNetUser wrote: I know I always burn CD-R, but I can't vouch for what the person that burned the original over a year ago did. And the copy the regulator sent us in on a CD-RW. I see -- there's no way to know about the original. Yeah... That's my problem. Unless I can explain it, the regulator won't just accept that mistakes happen and CDs can "go bad" or be burned bad. We've since initiated new procedures in place to prevent this in the future, but I was hoping maybe if I could provide anecdotal evidence of something similar happening previously, it'd help. I've looked through the support discussion groups on the Roxio website and this newsgroup and the web in general, but so far, no concrete examples of something similar happening to someone else. I burned a dozen discs today, using different parameters and intentionally trying to create a "bad" CD that looks similar. No luck yet. Have a conference call with the regulator on Monday and then maybe a trip to do a face to face meeting. |
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