Tape vs disk cost

[Jerry Feldman]

On 03/28/2010 11:17 PM, Mark J Dulcey wrote:
> On 3/28/2010 9:45 PM, Jack-rp9/bkPP+cDYtjvyW6yDsg at public.gmane.org wrote:
>  =20
>> Long term stability of tapes is also an issue.   LTO's have a timing
>> track pre-recorded, so it
>> should help.   Sofar I haven't found any really good archive media
>> (like rock-stable 50 year life)
>> that has any reasonable access time and cost per unit, including r/w d=
evice.
>>    =20
> My point was not that tape has no issues -- I know it does. But at leas=
t=20
> they're reasonably well known from years of experience. I don't know if=
=20
> anybody really knows what happens to hard drives that are shelved for=20
> years; the closest thing would be the track record of removable disk=20
> cartridges, which used to be popular once upon a time. And the=20
> technology of nearly all of them is so radically different from modern =

> hard disks that it likely doesn't mean much.
>
>  =20
>> The current best I have found for large amounts of data is tape (in
>> some reasonably current form),
>> or 'archival DVD's.
>>    =20
> The problem with DVDs is that their capacity is so small compared to th=
e=20
> size of modern hard disks that it takes a ridiculous number of them to =

> do a full backup. Do you have the patience to create a FOUR HUNDRED DIS=
C=20
> backup set for your 2TB hard drive?, Oh, alright, if you use dual layer=
=20
> discs you'll only need 250 of them. (Numbers rounded but you get the=20
> idea.) BD-R would be somewhat better but it hasn't been around long=20
> enough to say whether it will be useful for archiving.
>
> I do expect that we'll see at least one more generation of optical disc=
=20
> technology. The television industry is busy working on "4K" technology =

> (there are already cameras that record at that resolution being used fo=
r=20
> digital movie making) -- in other words, televisions with about double =

> the pixel count in each direction compared to 1080p. Combined with 3D, =

> the current 50GB Blu-Ray discs won't be up to the task, so we'll see=20
> some future disc standard (likely a Blu-Ray variant with more layers=20
> and/or higher pit density; such discs have already been demonstrated). =

> But whether we'll see a computer version, and at what price, remains to=
=20
> be seen.
>
>  =20
Personally, I think that optical media is not a very good backup for the
reasons stated, and in general computer generated optical disks have
also shown they can deteriorate. Today for home backup the best
solutions are most likely either a hard drive or a secure online
service, such as Carbonite. There are some very different strategies for
home vs. work.

--=20
Jerry Feldman <gaf-mNDKBlG2WHs at public.gmane.org>
Boston Linux and Unix
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