[wplug] DVD compatibility

[Bill Moran]

Mike <techmike at gmail.com> wrote:

> How old are the DVD-ROM drives you tried?  I've got a NEC-1300a (4x
> dual format) burner and using no name DVDs the only drives that cannot
> read them are much older drives.

One is very old (first generation DVD reader) and one is only a month
old, but it's a laptop drive.

> I know you said DVD-R, but are they actually DVD+R or DVD-R discs? 
> I've noticed DVD+R discs seem to be much less compatable with other
> units then -R discs.

Yes.  We were very careful to get DVD-R.  When we first noticed the
problem, we purchased another brand of DVD-R, the most expensive we
could find, in an attempt to rule out media.

> In testing I burnt one large 4.6gb file containing random data and
> it's md5, then did md5sum -c on the machine I wanted to test
> compatibility with..  That should give some confidence if the backups
> will work or not.. :)

I'm not getting across exactly what is happening:

1) DVD-R burnt by this drive NEVER work in the other 2 drives.  They
   don't even work partially, the other drives claim the disk is
   corrupt and won't provide a directory listing at all.
2) While we have had a few bad burns, _most_ of the time the resultant
   DVD is completely readable in the drive that burnt it, and the
   data is intact when tested.

Thanks for the input.

-- 
Bill Moran
Potential Technologies
http://www.potentialtech.com