HCHTech
Well-Known Member
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- Location
- Pittsburgh, PA - USA
I just finished a project recovering data from old CDs for a client, and thought I would summarize the process.
All of the disks were burned with some unknown program back in the 90s - so 22 to 25 years old.
None of the disks were physically damaged in any way that I could see, but most of them would not read correctly in Windows. There were 14 disks in all, 4 of them read fine straight away and I copied the data without incident.
I carefully cleaned the others with a rag dampened with mild soapy water. They all had paper labels on them (yuk), so I wanted to not destroy those if possible. This allowed me to read and save 2 more disks.
Next, I decided to try a different CD Drive. I mounted a brand new drive in my bench machine, and tried again. 2 more of the disks yielded to this process, 8 down, 6 to go. I don't know why a different drive made a difference. Something something, laser alignment something, I guess.
I then wondered if the speed of the drive had anything to do with it. I dug through my graveyard of broken computer dreams and found the oldest CD drive I had, probably early 2000s, I'd guess. It was IDE. One of my bench machines had an IDE header on the motherboard, so I cleaned up the drive, especially the read lens, mounted it and tried all of the remaining disks. I was getting into this project now and feeling very clever. I must have told the universe this, because none of the remaining disks would read in that old drive. Fail.
I took a break for lunch and it finally hit me to try ddrescue - don't know why my brain didn't offer this up sooner - data is data, no matter the medium...right?. One quick google later, I found this blog entry talking about ddrescue settings for CDs.
To my surprise, first passes at least are pretty fast - probably just because the data set is so small compared to hard drives. Anyway 20-30 minutes later, I had about 90% of the data from the first disk I tried.
All in all, it took a few of days of ddrescue runs, but we were able to get approximately 98% of the data from the remaining 6 disks. I put everything on an external hard disk and delivered it back to a very grateful client...along with an invoice, of course.
All of the disks were burned with some unknown program back in the 90s - so 22 to 25 years old.
None of the disks were physically damaged in any way that I could see, but most of them would not read correctly in Windows. There were 14 disks in all, 4 of them read fine straight away and I copied the data without incident.
I carefully cleaned the others with a rag dampened with mild soapy water. They all had paper labels on them (yuk), so I wanted to not destroy those if possible. This allowed me to read and save 2 more disks.
Next, I decided to try a different CD Drive. I mounted a brand new drive in my bench machine, and tried again. 2 more of the disks yielded to this process, 8 down, 6 to go. I don't know why a different drive made a difference. Something something, laser alignment something, I guess.
I then wondered if the speed of the drive had anything to do with it. I dug through my graveyard of broken computer dreams and found the oldest CD drive I had, probably early 2000s, I'd guess. It was IDE. One of my bench machines had an IDE header on the motherboard, so I cleaned up the drive, especially the read lens, mounted it and tried all of the remaining disks. I was getting into this project now and feeling very clever. I must have told the universe this, because none of the remaining disks would read in that old drive. Fail.
I took a break for lunch and it finally hit me to try ddrescue - don't know why my brain didn't offer this up sooner - data is data, no matter the medium...right?. One quick google later, I found this blog entry talking about ddrescue settings for CDs.
To my surprise, first passes at least are pretty fast - probably just because the data set is so small compared to hard drives. Anyway 20-30 minutes later, I had about 90% of the data from the first disk I tried.
All in all, it took a few of days of ddrescue runs, but we were able to get approximately 98% of the data from the remaining 6 disks. I put everything on an external hard disk and delivered it back to a very grateful client...along with an invoice, of course.
