What happened to DVD writing?

[Richard Mahlerwein]

>From: Warren Block <wblock at wonkity.com>
>Subject: Re: What happened to DVD writing?
>Date: Sunday, September 20, 2009, 2:58 PM
>>On Sun, 20 Sep 2009, Zaphod Beeblebrox wrote:
>>>
>>> FreeBSD lightning 7.2-STABLE FreeBSD 7.2-STABLE #0: Sun Sep 20 07:25:58 MDT
>>> 2009      root at lightning:/usr/obj/usr/src/sys/LIGHTNING  i386
>>>
>>> Now growisofs starts, but appears to never manage to write to the DVD. It's
>>> a DVD-R, one from the same batch that has worked before:
>>>
>>>  0.77% done, estimate finish Sun Sep 20 07:55:57 2009
>>>
>>> and there it stops.  Rebooting is needed, and the machine can't quite bring
>>> itself to shut down after syncing buffers.  /var/log/messages:
>>>
>> Another possibility is that the drive is worn out.  DVD writers have a
>> limited lifespan largely measured by the number of disks they cut.
>
>This drive has probably written under 50 DVDs, all ISOs used for backup. 
>It's a Lite-On DH-20A4P bought in August 2008.  It's looking like the 
>drive itself has failed.  Which seems odd, since I thought it could 
>still burn CDs.

I have had several exhibit behavior even more odd.

The most unusual was this particular CD writer... It read both DVDs and CDs but would write neither (it had worked fine the week before).  I took it out of the drive bay and hooked it to another PC to test and it worked fine there.  I put it back in the original PC and it failed.  I was swapping things around on that PC (assuming bad cable, bad power, etc) and had it sitting loose on the desk and found that it now worked again.  Put it back in the drive cage and it again would not write, though reading was fine.  Anyway, I finally figured out that even slight pressure in on the sides where it mounts would make it fail to burn CDs.  The cage itself exerted a bit of pressure and that was enough to make it fail at any attempt to burn a CD.

-Rich