I thought I would reopen this thread because I am at a point where
long-term archival is of concern and my drives are bursting at the
seams.
After some catastrophic losses early on (circa 1997), I have always
bought hard drives in pairs and periodically mirrored the copy. With
HDDs < $100, this is a very economical way of protection, even if the
copy is done manually. My goal with this was to protect against sudden
loss in the case that the drive did not spin up, which seems to happen
every few years. I also use TimeMachine on the Mac to backup my OS in
case of a similar OS drive failure. For my active data (OS and
recordings), redundant spinning drives are key. Whether you are using
some sort of NAS or other array for storing redundant copies, this
sort of backup is not archiving (as we have talked about).
On to archival.
My question is really this: Is a physical storage medium like DVD or
Blu-ray (optical discs) inherently more stable than an
electromechanical one like a hard disc drive (HDD)? My hunch is yes
for one primary reason. The storage medium and the playback mechanism
are decoupled. While the variables that would affect disc failure vary
between mediums, a HDD has quite a number of more potential points of
failure than an optical disc. In an HDD, not only could the data get
corrupted, but the platter could fail in a number of places. In an
optical disc, if your drive fails, just find another.
Beyond this, I am not confident that if I place a HDD on the shelf
that in 10 years it will spin up - in fact from my experiences, I have
not had a HDD last more the 5 years(!). All the other issues of
digital archival still remain of course. The refreshing of the storage
medium as the technology changes, periodic verification of the media,
and the ability to find interfaces or players that can read the data
assuming it survives.
At the moment, I am looking into acquiring a Blu-ray writer. The discs
are reportedly more robust than DVDs and promise a longer shelf life,
the capacity is far greater, and the price per GB is almost on par
with a HDD with Blu-ray at about $0.08 per GB.
Any thoughts/comments?
There is another storage medium that I have found incredibly stable:
the solid state drive. This technology is incredibly promising for
archival. We already use it daily in our recorders. In fact, we should
sure reopen this discussion once the cost per GB, now about $2+, is at
a point that is more reasonable.
David
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