[ale] burning blu-ray discs

[Jim Kinney]

Solid state devices suffer more from p-n-p junction boundary layer creep
than spinning disks suffer from  magnetic dipole dispersion. To slow the
degradation of SSD down, seal them in vapor-proof plastic with a desiccant
and keep them very cool. A freezer would be good. Cold temps also
dramatically raise the energy barriers around the capacitor cells that
comprise the actual bits in solid state storage. Higher exit walls means
less chance of leakage. Not so much "bit rot" as "bit wandering" :-)

The issue with hard drives is the seals and lubricant in the bearings were
designed for use not storage. But use incurs risk of failure. Storing the
drives for extended time (years) thus has a distinct and growing failure
option spinning up the disk. Remember the old (ancient) apple external
drives that required a "thump" on the case to get them to spin up? That was
after only 2-3 years of use. (OK. And drive have become much better.)

The 5 years lifespan of a hard drive is versus the anticipated 1000 years
of the mdisk. Yeah. That totally kicks it! Not sure if they actually
warranty the disk for that long or what your recourse will be if 600 years
from now your carefully stored movie collection begins to disintegrate.


On Wed, Aug 13, 2014 at 4:16 PM, JD <jdp at algoloma.com> wrote:

> Thanks, but aren't HDDs for archival like - 40 yrs on a shelf?
>
> My google-fu found this:
>
> http://serverfault.com/questions/51851/does-an-unplugged-hard-drive-used-for-data-archival-deteriorate
> which makes a case AGAINST using HDDs.
>
> I've never had a HDD refuse to spin up after being on a shelf, but ...
> there is
> always tomorrow. ;)  There are probably a few 80G WDs around to test with -
> they've been unplugged at least a decade - maybe longer.
>
> Also - the cheap optical media I've used ($20/100 discs) doesn't seem to
> fail as
> quickly as others report.  Only about 5 discs have shown any bit errors
> since
> 2004-ish. The data is validated when retrieved using 10% par/par2 files.
>  All
> data has been reconstructed with the help of the par2 files so far.
>
> So ... the m-disk stuff seems smarter for longer-term, important, storage.
> I'm
> convinced.  BTW - I didn't think that $140/25 25G discs was expensive -
> compared
> to a spinning HDD - it is just a tiny bit more, but 5 yrs vs 100+ yrs?
> SOLD!
>
> Wanted to ask about using SSDs for archival storage ... I have an unused
> 16G
> SATA M.2 SSD - that should easily store any critical household records
> "forever", right? ;) Since it is unused and doesn't have any moving parts
> - that
> means "forever".
>
>
>
> On 08/13/2014 03:40 PM, Jim Kinney wrote:
> > The m-disk reads like a Cd/DVD/Blu-ray but the data doesn't degrade. It's
> > extrapolated lifetime is 1000 years based on Navy stress testing.
> > It's only for archival storage. Uses a special burner (that doesn't cost
> > but maybe a few dollars more than a normal one) to write the disks. Any
> > reader can read them.
> >
> > Typical lifetime of a spinning disk (in use) is 5-8 years (for enterprise
> > grade, 24-7 on line). Tape's can last 20-30 years with proper storage
> (LTO6
> > 2.5TB is rated for 30 years with proper storage and costs $60/tape - the
> > drive is $4k)
> >
> > The mdisk is a specialty archival media. Think financial records, tax
> > records, family records, etc. or 42 thousand pictures of your cats per
> > blu-ray disk :-)
> >
> >
> > On Wed, Aug 13, 2014 at 3:06 PM, JD <jdp at algoloma.com> wrote:
> >
> >> On 08/13/2014 10:25 AM, Jim Kinney wrote:
> >>> M-Disc Bluray Recordable Media 25 GB Branded (25 Disc Pack) $130
> >>
> >>
> >> Guess I'm just confused by optical media these days. It isn't cheaper,
> >> isn't as
> >> convenient, it isn't re-writable 100,000x AND costs more than a spinning
> >> disk.
> >>
> >> I suppose if there are HIPPA or other regulatory requirements, but in a
> >> house?
> >> What am I missing?
> >>
> >> BTW, I have over 1,000 backup DVDs here (mix of 4.7 and 8G) ... but
> stopped
> >> using optical when HDDs became less expensive.  Slowly moving those to
> >> 2+TB HDDs
> >> that can be connected via a USB3 dock.
> >>
> >> Can someone please enlighten me?
> >>
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-- 
-- 
James P. Kinney III

Every time you stop a school, you will have to build a jail. What you gain
at one end you lose at the other. It's like feeding a dog on his own tail.
It won't fatten the dog.
- Speech 11/23/1900 Mark Twain


*http://heretothereideas.blogspot.com/
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