dd won't copy CD

dosnlinux · 06-27-2006, 03:15 PM

I'm trying to make an image of a cd, but every time I try I can only get 1.5MB of it. The cd has at least 500MB of data.

I used "dd if=/dev/hdb of=mycd.img" and with "dd if=/dev/hdb of=mycd.img bs=2048 conv=notrunc"

here's the output of dd

Code:

dd: reading `/dev/hdb': Input/output error
2984+0 records in
2984+0 records out
1527808 bytes (1.5 MB) copied, 176.537 seconds, 8.7 kB/s

Also, the CD isn't mounted.

Thanks for any help you can give.

320mb · 06-27-2006, 03:40 PM

you are better off using the "cp" command with attributes like:

Code:

cp -Rav

haertig · 06-27-2006, 04:42 PM

Are you sure your CD and/or drive is good? dd is reporting an IO error. And also, taking 176 seconds to copy 1.5Mb of data is not exactly the zippiest performance...

dosnlinux · 06-27-2006, 09:22 PM

I've made images from other CD's around the time I tried to make an image of this one with no trouble. It seems to be just this disk.

Could finger prints or scratches cause this kind of problem? After taking a quick glance at the disk's surface nothing looked too out of the ordinary, but that doesn't mean they're not there.

jschiwal · 06-27-2006, 09:48 PM

Try cleaning the disc. If you still get the IO error try the "conv=noerror" option. This will cause dd to continue copying even if there is an error. You might want to set both the block size and count values in the dd command before trying it. The image file will still contain errors, but hopefully it will be a usable as the disc.

haertig · 06-27-2006, 10:01 PM

Quote:

Originally Posted by dosnlinux

Could finger prints or scratches cause this kind of problem?

Could be. If you decide to clean the disk, just use water and dishwashing liquid and scrub with your fingers (fingers are soft and don't scratch!) Then blot dry on a soft towel, don't rub. If you feel you MUST rub slightly, rub outwards in radial lines, not circular "around" the disk.