Gary Dale <garydale@rogers.com> wrote:
> Jerry Peters wrote:
>> Gary Dale <garydale@rogers.com> wrote:
>>> Gary Dale wrote:
>>>> Jerry Peters wrote:
>>>>
>>>>> I've never had any problems, other than DVD-RAM tends to be slow and a
>>>>> large amount of buffered writes tend to build up (fixed by mounting
>>>>> with the sync option).
>>>>>
>>>>> What's the "trouble" with working with UDF? My DVD-RAM mounts on
>>>>> /dev/sr0 in rw mode and I copy data to it, just as if it were a large
>>>>> floppy. That's the advantage of DVD-RAM over the other DVD whatevers,
>>>>> it behaves like a large floppy, no special formatting required.
>>>>>
>>>>> If you really must use growisofs, get the source and change it to your
>>>>> needs then.
>>>>>
>>>> I actually just tried using UDF directly and I found what the problem
>>>> is. :)
>>>>
>>>> It appears that there is a bug in UDF support that isn't fixed until
>>>> 2.6.22 (this is from the Wikipedia -
>>>> http://en.wikipedia.org/wiki/Universal_Disk_Format) that limits you to
>>>> file sizes of no more than 1G. I tarred and zipped the files before
>>>> backing them up to save space (even then the tarball is almost 3G), so
>>>> my backups failed.
>>>>
>>>> Still, the growisofs problem of wanting a clean disk bugged me, so I've
>>>> switched over to ext2 for now. I test for a file system by trying to
>>>> mount it as ext2. If it fails, I format it then mount it.
>>>>
>>>> Of course, this is not the file system anyone expects on a DVD-RAM disk,
>>>> so I will give UDF a try again when Debian/lenny becomes the new stable
>>>> release in a couple of years.
>>> I'm back to about the only method that seems to be reliable.
>>> - mkudffs /dev/dvd -- to blank the DVD-RAM so growisofs will use it
>>> - growisofs -Z /dev/dvd /backups
>>>
>>> For some unknown reason, mke2fs /dev/dvd fails, or if it succeeds, it is
>>> unreliable for writing. I may or may not get a complete cp /backups/*
>>> /media/dvd but even if I do, I may not be able to mount it again. And
>>> even if I can mount it again, there is no guarantee that subsequent cp's
>>> will work.
>>>
>>> In short, working with DVD-RAM seems to be an exercise in frustration
>>> even though it is the only game in town for doing repetitive backups.
>>> It's supposed ability to be usable just like a hard disk is a myth, at
>>> least until kernel 2.16.22.
>>
>> Never tried ext2. I do use some vfat formatted disks because Win98
>> will not consistently recognize UDF DVD-RAM disks (it does recognize
>> DVD-ROM's however). Never had any problems except that vfat on DVD is
>> slow, of course vfat is slow on a large HD too.
>> Could you be having some incompatablity problems with the DVD drive
>> itself? Ext2 should work, and modern drives are supposed to handle bad
>> sectors internally.
>>
>> Jerry
>
> I thought perhaps the issue was one of having to do an eject between
> operations but my testing gave me similar results with or without an
> eject. The main difference is that sometimes it takes two mounts after
> an eject - I guess mount times out a bit too fast. This makes testing
> for a successful mount a little trickier.
>
> I'm going to stick with growisofs for now, unless it starts giving me
> headaches. If it does, I'll try vfat.
>
> Thanks.

I have 2 different DVD drives, one's a Matsushita and the other is an
LG. I have a number of DVD-RAMS that the Matsushita has trouble
recognizing (the light blinks seemingly forever) while the LG drive
recognizes them without any long delays. I had considered these disks
as defective until trying them in the LG.

Jerry