[Info-vax] Media failures, was: Re: grey screen of death

[David Froble]

Simon Clubley wrote:
> On 2015-05-24, Stephen Hoffman <seaohveh at hoffmanlabs.invalid> wrote:
>> On 2015-05-24 16:30:46 +0000, Simon Clubley said:
>>
>>> I meant what I said about bitrot BTW; I've just retired a HP USB stick 
>>> which had started flipping the bits in some files which had been 
>>> unchanged on the USB stick for a while; the verify pass caught it after 
>>> some unrelated files were added to the same backup partition on the USB 
>>> stick.
>> Um, so?   CD and DVD media also degrades, too.  Sometimes badly.   I've 
>> had mis-recorded DVD disks arrive locally, and have had verified media 
>> fail in short order.   Batches of bad media from well-known vendors 
>> have occurred, too.   Some of the 9-track tape media shed the recording 
>> substrate all over the spools and all over the tape drive heads.   
>> You've undoubtedly experienced other problems and other failures with 
>> other media, as have other folks.
>>
> 
> It's about failure rates Hoff. I can't remember a DEC/CPQ/HP supplied
> CD/DVD failing on me but I have seen multiple flash drive failures,
> including branded ones. That's why I would prefer DVDs instead of flash
> drives for any future software distribution.
> 
> As for 9 track tape, let's just say I'm glad it's a part of ancient
> history. :-)
> 
> As for locally burnt DVD media, the majority of failures occur during
> burning so you know about it right away. I have had DVDs go bad some
> time after burning, but off the top of my head, I can't put a figure
> on the frequency. I do perceive locally burnt DVD media as more reliable
> than flash drives however.
> 
> Simon.
> 

Want to see it go bad?  Sit it in the sun for a while.  (Ask me how I 
know that.)  Lesson learned ....