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I saw from another post how to do this: by using

cat (optical disc device) > (ISO file on regular disk)
e.g.,

cat /dev/sr0 > /z/windows7.iso

When I tried it, it goes partially then gets

cat /dev/sr0: Input/Output Error

This happens at about 20% completed on one of the DVDs and maybe 3% on the other one.

NB: these are LEGAL original Windows installation DVDs that I had successfully installed on older (now defunct laptops). It is very unlikely that both DVDs became corrupted/damaged. This has to do with the copying, not with the original media.

Here is output:

steve@mithril:/z$ cat /dev/sr0 > /z/windowsxp.iso
cat: /dev/sr0: Input/output error
steve@mithril:/z$ ll /z/windowsxp.iso
-rw-rw-r-- 1 steve steve 652869632 Jul  6 13:11 /z/windowsxp.iso
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I'm confused; your question title says CD, and you show a file that is 652M bytes, which is about right for a CD.  I think maybe you're getting a complete, good copy, and a stupid, incorrect error message.  What evidence do you have to contradict my theory? – G-Man Aug 12 '15 at 1:54
up vote 0 down vote accepted

Try using dd. sudo dd if=/dev/sr0 of=/path/to/output/file.iso

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That yields an immediate "dd: reading '/dev/sro': Input/Output error. But wait, i tried a second time and it appears to have worked. Will get back. – javadba Jul 6 '13 at 20:35
    
Should be sr0 not sro :D. If you did actually type sr0 then Are you sure sr0 is the device file for the CD? Did you use sudo? And have you unmounted the CD before trying this? – w4etwetewtwet Jul 6 '13 at 20:36
    
i just "historied" the same command it appears to have worked second time. – javadba Jul 6 '13 at 20:37
    
One of the two did "dd" properly but vmware installation failed, possibly unrelated. But for the other, it still only completed 3% before Input/Output error. I am going to try to install directly on old computer to prove one way/other if/not it were media problem. – javadba Jul 6 '13 at 20:49

I would use safecopy instead of cat or dd.

safecopy /dev/sr0 out.iso

It's in the standard software repositories, and is specifically designed for this kind of thing. From the man page:

Safecopy is a data recovery tool which tries to extract as much data as possible from a seekable, but problematic (i.e. damaged sectors) source - like floppy drives, harddisk partitions, CDs, ..., where other tools like dd would fail doe to I/O errors.

Safecopy tries to get as much data from the source as possible without device dependent tricks. For example to get an ISO image from a copy pro‐ tected or otherwise damaged CD-ROM, cdrdao and bin2iso would possibly do a better and faster job.

Similar answer here: http://askubuntu.com/a/138871

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