Re: CD as backup (off topic - long)

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From: Phillip Murphy (pmurf@bellsouth.net)
Date: 12/03/02-05:55:14 PM Z


I believe that you're most safe with two or even three different media to hold
your files. Magneto Optical Disks appear to be the safest bet, however, they
can be prohibit ably expensive. Most of my files are either on hard disks (on
two different machines) or on CD-R or DVD-R media. Something to note is that
no two CD-Rs are necessarily alike chemically. (read that as some are less
reliable than others). Lasers are tuned to particular media, although some
have a broader range of use than others. Practically, this means that a CD-R
burned in CD_drive-A may play perfectly in CD_drive-A but not at all in
CD_drive-B.

It gets more complicated when you begin using DVD media because you need to
choose between DVD-RAM, DVD-R (general purpose), DVD-R (authoring), DVD+R,
DVD-RW, DVD+RW and not to mention the soon to be released blue-laser-DVD's.

I recommend Mitsui media because of the unique Phthalocyanine
(tha-lo-sy-a-neen) chemistry that they use. Audiofiles have known about them
for years now.
(they claim that they can hear the difference when recordings are burned to
this media). I use both their CD-R gold media and their DVD-R media with
excellent reliability. I purchase my discs at CDW, however, one can buy
direct from Mitsui now.
http://www.mitsuicdr.com/products/general_information.html.

When I need a quick burn for use on the "sneaker network", I'll use any stack
of discount CD-R media (20 to 28 cents a piece). Do the math on that compared
to any Zip media. A 40x burner has me waiting for a few seconds using Toast.
A full 650MB CD-R will take three minutes.

Disc media needs to be kept from too much light, heat, humidity, and
pressure. Tyvek makes a good storage material because it's inert and doesn't
out gas like
some plastics that can break down the dyes. Another thing is not to write on
your discs with solvent based inks (e.g. Sharpies) If you look hard enough
you
can find water based "sharpies" that will not effect the media.

One last thing; what do you do with all of those CD's and DVD's floating
around?? I use a DVD/CD jukebox from Powerfile.
http://www.dvdchanger.com

This will hold 200 DVD's giving me close to a terabyte of storage. It has two
drives and every disc is catalogued using Canto Cumulus 5.5 so that I have
ready access to all of my images. A second set of discs go into tyvek lined
boxes and stored in another part of the building. (off site would be better)

best regards,

Phillip

Judy Seigel wrote:

> On Sun, 1 Dec 2002, Clyde Rogers wrote:
>
> > > BTW, just for the record, a 4 X 6.5" scan of a color negative at 2400
> > > dpi gives a raw file of almost 400mb. Think my most important need is
> > > to replace the 100mb Zip drive with a 750mb version.
> >
> > Burn CDs---more reliable, more universal (it will be easier to read a
> > CD than a 750 Zip 20 years from now), and much cheaper.
>
> If the information is extremely important, I think maybe you want both
> belt and suspenders -- I've had both systems (CD & Zip) go bad. Recently
> transferring from CD's to new hard drive, on 2 out of 3 CDs I got message
> of skipped individual files (I forget the wording, but it said in effect,
> forgetabout it).
>
> The next day I had a zip disk do so-called click of death -- continued
> clicking in the tray and wouldn't transfer a file to hard drive -- though
> it did eject. My internal zip drive still seems OK, so I assume it was
> just that disk.
>
> In both cases, I have other backups, and the old CPU also has the info &
> can (theoretically at least) be accessed, but I point out that NO SCRATCH
> or other visible manifestation could be detected on the CDs that bombed.
> My theory is that ESPECIALLY with so much info, the CD is exceedingly
> casual about any particular file.
>
> The zip drive is also a much more practical back up for ongoing work --
> after a day, or even an hour, of work I may have a relatively small file
> that I wouldn't use a CD for (since they have to be done at one stroke),
> but can in 5 seconds back on the zip disk always onscreen. In fact I hear
> with amazement of folks whose hard drives crashed leaving them ENTIRELY
> UNBACKED. I don't like to tempt the digitons who have a grudge against me
> from a prior existence, but my thought is that those folks did NOT have a
> zip at hand.
>
> Judy


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