DVD burning..

Greg 'groggy' Lehey grog at FreeBSD.org
Fri Aug 5 04:39:52 GMT 2005

On Wednesday,  3 August 2005 at 14:51:06 +0200, cpghost wrote:
> On Tue, Aug 02, 2005 at 10:22:19AM +0930, Greg 'groggy' Lehey wrote:
>> of coasters, and it might help identify the issues.  All my burn
>> failures (about 40% of total!) have been with DVD+Rs, though
>> admittedly a cheap no-name brand bought in Taipei.  I've found that
>> they work OK if I burn them at speed=1; if I use the default speed of
>> 4, they usually fail.
> Same here. DVD+R fail for me at a similar rate, though DVD-R from
> the same brand are doing just fine.
> What's puzzling is that growisofs doesn't always notice errors
> while burning. Approx 1/3rd of errors are first detected while reading
> the DVD+R back in (MEDIUM ERROR READ BIG etc..). OTOH, I'm adding and
> later checking md5 checksums for every file; and I've never had a
> checksum mismatch. If something goes wrong, it's the whole reading of
> a sector or a bunch of sectors.

I don't think that's puzzling.  Writing doesn't imply reading; if the
drive thinks it has written the data, you can't find out whether the
medium has also stored it until you read it back.  You'll note that
the script I mentioned (http://www.lemis.com/grog/making-AUUGN.html)
includes a separate verify step.  Based on my experience (and yours
:-), I'd strongly recommend always verifying.

New discovery about ISO file systems (today): you can burn symlinks to
DVD, and they'll work under FreeBSD and Linux.  They fail under

When replying to this message, please copy the original recipients.
If you don't, I may ignore the reply or reply to the original recipients.
For more information, see http://www.lemis.com/questions.html
See complete headers for address and phone numbers.
-------------- next part --------------
A non-text attachment was scrubbed...
Name: not available
Type: application/pgp-signature
Size: 187 bytes
Desc: not available
Url : http://lists.freebsd.org/pipermail/freebsd-questions/attachments/20050805/83a8e2a1/attachment.bin

More information about the freebsd-questions mailing list