Damaged CDs and DVDs cause VFS: busy inodes errors

conn-fused · 02-28-2006, 02:58 PM

I have a number of CDs and DVDs which have errors on them. All were burnt under k3b on a Mandrake 10.1 system. K3b's verification process detected the errors. Reburning the same files would recreate the errors, so it seems clear that there was a problem with the files, although they were fine on the hard drive.

If I insert one of these discs and then try to read, copy or otherwise access a damaged file the CD will spin constantly. The acting konsole will hang. The process acting on the file cannot be killed, even with a "kill -9" command. The disc apparently cannot be unmounted. Only manually ejecting the disc will stop the acting process. This happens on both Mandrake 10.1 and Mandriva 2006.

After this, inserting any CD or DVD results in the logs being filled with entries like this:

Code:

kernel: hdc: tray open
kernel: end_request: I/O error, dev hdc, sector 8492628
kernel: hdc: tray open
kernel: end_request: I/O error, dev hdc, sector 8492632
kernel: hdc: tray open
kernel: end_request: I/O error, dev hdc, sector 520
kernel: VFS: busy inodes on changed media
last message repeated 77 times
last message repeated 86 times

Nothing I've found, except rebooting, will stop this. It's as if the read or copy process acting on the damaged file is still trying to access it even though it no longer appears under "ps ax".

So, does anyone have any idea what to do after reading such a disc (and/or how to repair such discs)?

stress_junkie · 03-02-2006, 09:16 AM

I suspect that you are using cheap media or a cheap burner.

Quote:

Originally Posted by conn-fused

Reburning the same files would recreate the errors, so it seems clear that there was a problem with the files, although they were fine on the hard drive.

Why do you think that? Have you done it?

Quote:

Originally Posted by conn-fused

If I insert one of these discs and then try to read, copy or otherwise access a damaged file the CD will spin constantly. The acting konsole will hang. The process acting on the file cannot be killed, even with a "kill -9" command. The disc apparently cannot be unmounted. Only manually ejecting the disc will stop the acting process. This happens on both Mandrake 10.1 and Mandriva 2006.

Unfortunately this is not unusual for Linux. Trying to mount a device that isn't working properly can result in the system getting hung for quite a while. It will eventually give up but it takes too long to time out and, as you say, it doesn't respond to kill signals.

Quote:

Originally Posted by conn-fused

After this, inserting any CD or DVD results in the logs being filled with entries like this:

Code:

kernel: hdc: tray open
kernel: end_request: I/O error, dev hdc, sector 8492628
kernel: hdc: tray open
kernel: end_request: I/O error, dev hdc, sector 8492632
kernel: hdc: tray open
kernel: end_request: I/O error, dev hdc, sector 520
kernel: VFS: busy inodes on changed media
last message repeated 77 times
last message repeated 86 times

Nothing I've found, except rebooting, will stop this. It's as if the read or copy process acting on the damaged file is still trying to access it even though it no longer appears under "ps ax".

So, does anyone have any idea what to do after reading such a disc (and/or how to repair such discs)?

If you are using a $25 burner then I recommend that you get a better one. I only use Sony disk burners and I've never had a problem. I have tried other respected brands such as Plextor but only the Sony drives have worked as advertised without problems. As far as media goes I use both cheap and expensive media. I find that the cheap media takes much longer to burn but the data verifies correctly. Still, when I use the Sony media the data burns fast and it always verifies correctly.

conn-fused · 03-02-2006, 02:45 PM

Thanks for the reply, but:

Quote:

Reburning the same files would recreate the errors, so it seems clear that there was a problem with the files, although they were fine on the hard drive.

Why do you think that? Have you done it?

Yes, I have done it. I suppose it would have been clearer if I'd written, "Reburning the same files recreated the errors, so..."

Quote:

Unfortunately this is not unusual for Linux. Trying to mount a device that isn't working properly can result in the system getting hung for quite a while. It will eventually give up but it takes too long to time out and, as you say, it doesn't respond to kill signals.

Hmm. That's unfortunate.

Quote:

If you are using a $25 burner then I recommend that you get a better one. I only use Sony disk burners and I've never had a problem. I have tried other respected brands such as Plextor but only the Sony drives have worked as advertised without problems. As far as media goes I use both cheap and expensive media. I find that the cheap media takes much longer to burn but the data verifies correctly. Still, when I use the Sony media the data burns fast and it always verifies correctly.

It's actually not a cheap burner. Nor is the media. Admittedly, the burner is getting older, so it could be involved. I'd even say that was likely, except for the fact that the errors recurred in the same files when I tried to reburn them. So I'm not sure I really accept your explanation.

But either way, right now I still have to deal with data recovery. Does anyone here have any experience in that area?