
When will there be cheap permanent mass storages for archiving? - c_void
As people are producing more and more data every day (pictures, videos in better and better quality), there must be a high demand for very large permanent storages. In my impression, the only way for mass storage is to buy expensive HDDs. While in the 90ies there were CDs, that could serve the market, there does not seem to be an equivalent to please today&#x27;s demands. There seems to be development in optical disk storages, but with at most 500GB (experimental) they are far below actual needs. Already 20 years ago the company Creo produced optical tapes that were able to store 1TB of data. What happened? What are the (technical and maybe commercial?) problems in building cheap mass storages for commercial use?
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svennek
First of all, permanent is a hard challenge, and CDs (as you mentioned)
generally was good somewhere between 1 and 10 years, not more. I know the
danish national library spends quite some time transferring archives from CD
to a newer CD.

I think backup tapes are still the best bet (as long as they are LTO-based).
Built for longetivity (some/most have stated lifespans of 30 years on a shelf,
YMMV) and an open format (i.e. three completely separate business building
drives that can read each others tapes).

The LTO tapedrives also do in-flight test of the writes (at full speed), so
that an failed write will never be unnoticed.

Actually they have a write head, then a read head then another write head and
another read-head.

When you write to the tape, writehead1 writes it and readhead1 checks it. If
it fails, it retries with writehead2/readhead2 .. If that fails too, the
backup is aborted and the tape is marked (in tapemedia-internal memory) as
bad.

The bummer for a private person is that even though the tapes themselves are
relatively cheap (around 200USD for a 6 TB tape, that can take up to 15TB
depending on compression rate of your content) the drives are expensive as
heck (due to a lot of smarts), think 5k USD range.

Another benefit is that if a drive goes bad, it can be exchanged without the
datamedia being exchanged as well (the same is true for CD/DVDs but not for
harddrives or SSDs).

But as always, if you don't have three copies (on different media/sites/...)
of your data, you actually don't have any copies at all.

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c_void
In the mid 90ies there were 9GB hard drives availabe, which is roughly the
same amount of data that fits on 14 CDs. Today we have 14TB sized HDDs, so an
equivalent optical disk should be able to store 1TB of data. However today a
private person easily has more than one device plus several external HDDs to
store his or her data. So I guess it would not be too greedy to demand
permanent media with a capacity of 10TB. Comparing with CDs the price could be
2USD. So in this comparison I honestly find a 6TB tape for 200USD incredibly
expensive.

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drallison
C_void's question is ill formed. What do you mean by "cheap" and "permanent"?
What constitutes "mass storage"? "[A]chiving" suggests durability over time,
but how much time? What sort of access time would be acceptable?

The lede paragraph provides some context but is not explicit. What is the
application contemplated?

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c_void
You are right in that I was little explicit. Let us talk about a private
persons need and let us stay at the comparison with CDs as they were available
in the 90ies. In another reply I derived today's needed disk size as 1-10TB.
Let us also say that the access time should suffice to be able to watch a 4k
resolved movie. You say archiving suggests durability and CDs may not have the
same durability as tape storages. However I would say that a cheap price would
compensate a possible lack of durability, because one could easily duplicate
or restore important data.

