Re: Self-written DVD+Rs that cannot be read...
I would highly suggest trying to read the DVD's under another OS. There is
a Linux kernel bug regarding reading CD/DVD media related to the
read-ahead cache. It attempts to read data before it has been requested
to cache it. But on CD/DVD media the data can run out before the media
actually does. If these errors occur near the end of the data area then
likely problem. There are others here on the list that know a great deal
more about this problem than I do. I see it occasionally doing verified
backups. Where the verification fails near the end of the data backup.
And then a 2nd or 3rd verification will pass just fine. The writing
process will not report any errors because there were none. This issue
regards reading only and as I understand it at the end of the data area.
I hope I am not speaking without knowledge here. But if this is incorrect
then someone else please correct me.
Using the "dd" command to read back the data area until the error occurs
and then noting the amount of data that was readable compared to the
actual data recorded should indicate if it is the end of the data area or
not. If it is not the end of the data area but is erratic or just some
areas in the recording then bad/dirty media could cause these problems. I
would consider Verbatim as a known brand and good media, but that doesn't
mean the drive firmware has support for it.
Perhaps it will be of some help to you.
James
On Sunday 20 February 2005 02:45, Hugo van der Merwe wrote:
> I'm new to DVD writing. I've now got about 15 badly written DVDs.
> growisofs does not give any bad-looking output, everything looks great,
> but the DVDs all have some files that cannot be read. These kinds of
> errors appear in dmesg when trying to read the DVDs I've written:
>
> Buffer I/O error on device hdc, logical block 226047
> hdc: command error: status=0x51 { DriveReady SeekComplete Error }
> hdc: command error: error=0x54
> ide: failed opcode was 100
> end_request: I/O error, dev hdc, sector 904192
> Buffer I/O error on device hdc, logical block 226048
> hdc: command error: status=0x51 { DriveReady SeekComplete Error }
> hdc: command error: error=0x54
> ide: failed opcode was 100
> end_request: I/O error, dev hdc, sector 904196
> Buffer I/O error on device hdc, logical block 226049
> hdc: command error: status=0x51 { DriveReady SeekComplete Error }
> hdc: command error: error=0x54
> ide: failed opcode was 100
>
> I miss the output of cdrecord telling me about possible buffer underruns
> and the like. ("Burn-free was used 3 times" etc.) What can I do? I've
> tried giving the -speed=1 parameter, it still writes at about 4x. I am
> using Verbatim DVD+Rs, I suppose I should try something else. What else
> is "good quality"? Might Verbatim DVD-Rs work better? Or should I be
> trying a different drive? (Or install Windows to try other software -
> might that help at all, or is this purely a hardware problem?)
>
> Thanks,
> Hugo
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