dd fails to copy random discs: Input/output error

scorchgeek · 09-18-2011, 02:52 PM

I'm tired of swapping CDs in and out of my cdrom drive, and I'd like to be able to box up my 150-some discs and get them out of my way. So I've been using dd to make ISO images of all the discs (which I can then mount and be on my way without actually needing the CD, or burn a copy of if I need an actual disc for whatever reason).

That's all great. On about 4/5 CD's, dd works properly and I get an ISO file. But on the other 1/5 of the discs, it runs for a while and then says "dd: error reading /dev/cdrom: Input/output error." The ISO file always ends up smaller than it should be--sometimes a full disc will produce a 2MB ISO file this way. So, although I actually haven't tried mounting one, I know these are not valid discs.

I don't think the problem is copy-protection, though I could be wrong, because, for instance, when I attempted to produce images of SimCity 4, the first disc worked fine, but the second disc gave me the error. The discs that are failing are in perfect condition--in fact, all of the damaged discs I have produced a flawless copy.

My CDROM drive seems to usually run at a slower speed, without whirring up and making more noise, when it ends up producing an I/O error. (This isn't 100% true, but it usually is.)

The problem is, however, these specific discs--I can retry three or four times (after deleting the half-completed file), and I get the same result. As soon as I try a different CD, it works perfectly.

I tried Googling this issue for quite a while, and found some information on it, but nothing that seemed to apply to my exact situation. Has anyone had this happen to them before? Is there a workaround I could try?

teckk · 09-18-2011, 03:03 PM

Couple of thoughts.

1. Are the disks that fail to copy data CD's or audio CD's?
You can't make a copy of an audio CD that way.

2. Are the failed CD's getting mounted correctly before you try to make an image of them?
You can't mount an audio CD.

scorchgeek · 09-18-2011, 03:15 PM

No, they are all data CD's. (I'm sure they all have audio *on* them, but they are still data CD's.)

One of them (which is from the '90s) apparently has both an audio track that will play in a CD player and a data part, but since that is only one of the CD's I'm having trouble with, that can't be the problem in itself.

As for mounting, I tried with the disk both mounted and not mounted. In general, though, I think GNOME would have mounted the disks as soon as I put them in. I did try umounting it once to see if something else accessing it was the problem.

scorchgeek · 09-18-2011, 03:57 PM

I didn't think to try this before:

Code:

soren@Hackereth:~$ dmesg | tail
[37136.196931] sr 1:0:1:0: [sr0] Unhandled sense code
[37136.196937] sr 1:0:1:0: [sr0]  Result: hostbyte=DID_OK driverbyte=DRIVER_SENSE
[37136.196943] sr 1:0:1:0: [sr0]  Sense Key : Medium Error [current] 
[37136.196949] Info fld=0x330
[37136.196952] sr 1:0:1:0: [sr0]  Add. Sense: Unrecovered read error
[37136.196959] sr 1:0:1:0: [sr0] CDB: Read(10): 28 00 00 00 03 30 00 00 02 00
[37136.196977] end_request: I/O error, dev sr0, sector 3264
[37136.196982] quiet_error: 52 callbacks suppressed
[37136.196986] Buffer I/O error on device sr0, logical block 816
[37136.196991] Buffer I/O error on device sr0, logical block 817

scorchgeek · 09-18-2011, 04:13 PM

Okay, update: I tried doing the same thing on my server. It failed in the same place and dmesg gives almost identical output, down to the logical blocks and sectors being the same. So it seems there is something inherently wrong with the disk (at least this particular one).

As for what that is and how I might be able to go about fixing it, I'm still stumped.

jschiwal · 09-18-2011, 04:59 PM

If a disc might be an audio disc or a multi-session disc, you might try a CD burning program to duplicate the disc. For some you may have smudges or small scratches. Cleaning them may help. The problem could be your drive. I always have problems with internal CD/DVD drives after 6 mo. or so. External drives have always given me better luck.