[Gllug] Viable back-up solutions for gigabytes?

[John Hearns]

On Sun, 2004-09-05 at 10:34, Chris Bell wrote:

> > Writeable media such as this degrades over time - a comparatively short 
> > time.
> > 
>    Many years ago I purchased a magneto-optical drive with several discs.
> The media was guaranteed minimum 25 years data retention, nuclear blast
> proof, etc, but the discs were only 512/1024 MB, and the very expensive
> drive died within a comparatively short time.
>    
I've brought up the subject of 'data archaeology' several times on the
GLLUG list.
Its a subject which I like to mull over :-)

I remember MO drives like that - we used them for medical image storage
in one place I worked, and I also met them later at Framestore attached
to Henries.

Also I remember going to a meeting where someone refered to NASA's
problems. They have a warehouse full of round tapes of mission data,
where the tape substrate is separating from the oxide layer.
Lots of gentle handling needed to get the data off.
And round tapes suffer from 'print through' if they are not unwoaund
and re-wound every so often.


I think comments are often made that it 'would be easy to move data to
a new physical format' before drives or media deteriorate.
As you say, its more likely that the drivers are unobtainable or broken.
I wonder if any big project REALLY has done this.

In the medical imaging field, the requirement is to keep X-rays (and 
I includein that catch-all MRIs, CTs, PET< ultrasound, cariac
angiography) for ten years (might be mistaken).
Paediatric images kept till the child is 18 (again I might be wrong).

Is anyone really sure that digital data is moved on to the next storage
device when the current one reaches end-of-life?


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