[geeks] The Idea(tm)... Homebrew Terabytes Cheap

[Simeon Johnston]

What about the other tape mediums?
DLT -- A little less expensive than the HD w/ the same storage
capacity.  30 year lifespan -- These things will outlive you.
SuperDLT -- These look really cool.  Next generation of an awsome
product.  Same benefits larger capacity and speed.
AIT2 -- Also look really cool.  Never used these myself but have seen
the specs.

One thing I have been wondering about is compression.  I know that some
tapes compress using some sort of compression formula.  DLT tape drives
seem to be different and I thought all tape drives, at least the newer
ones, did the same thing.  If I understand it correctly, instead of
compressing the data the drive simply uses two write heads instead of
one.  This gives you more data per mm of tape and also doubles you
writing speed.
I know that this will not work with one headed tape drives but I was
under the impression that all newer drives were like this.
Am I wrong?

And you also have the option of DVD.
DVD seems to be a good media for this particular function.  More storage
than you DDS-2 tapes and the shelf life of a CD.  What could be better (
besides the price, which will go down over the time period you talking
about ).  Although there are still several different formats newer
drives should theoretically support the older formats ( yes, not always
true.  But still a good theory ).

I would go into pricing but don't have time rite now.  I think they are
in the same price range, roughly.
I know DLT is getting really cheap.

sim

Jody Stephens wrote:

> Here is the deal. Currently we have about 5 DDS-2 tape
> drives, media we get for ~$15 a pop. Problem, we have
> to keep all of the tapes for 1 year, after that we
> keep month beginnings and month ends. Each machine does
> about 2GB uncompressed.
>
> So we've been trying to think of way to cut costs (we
> seem to spend >$5000 yearly for tapes including about a
> %10 failure rate). Some of the things I've looked at are
>
> 1. Buying cheap IDE drives, writing to them, pulling them
> storing them. Actually this works out to about the same
> price, but we get better reliabilty (in theory), quicker
> backups and restores. But we have to deal with HD's, which
> are not exactlly durable. So that is out.
>
> 2. CD-R. Alright except each machine would span more than
> 1 disc, creating problems if one fails. And dealing with
> all those CD's doesn't sound like fun.
>
> 3. Optical. Too bloody expensive.
>
> Sooo... My thought.
> 10 IDE plex at ($460 each)
> 80 WD 40GB drives ($130 each)
> put these in a group of rackmount cases.
> Buy a decent machine with a bunch of memory.
> Buy a couple of good SCSI cards.
>
> Put these together with Linux (or OS of choice) and
> a couple of big slices. Bingo. For less than $20,000
> I just got 3.2TB max (probably would be less as
> I would want to make some hot spares and such). That
> gets me ~3yrs data. If I'm feeling crazy, I put together
> another one at the other store and let them mirror
> (safe from fire).
>
> This wouldn't really need to be a high performance beast,
> as data would basically be dribbling in. But I guess with
> more busess and some striping it could be a decent performer.
> If there is a way to get some drives to sleep, then power
> consumption would drop dramatically. It seems that the
> same company also makes a IDE backplane which makes some
> sort of hot swapping availble. WD gives a 5 year life span
> to the drive, but by then I'm sure you could just buy the
> new 300GB drives and stick them in (what is that... 240TB,
> good lord).
>
> For comparison Sun's A1000 gives 436GB for $22,220.00 or
> a nickel a MB compared to $20,000 for this system at
> 6/10 of a penny per MB
>
> Am I on crack? It just seems wrong.  Do I have some order
> of magnitude wrong here?
> What do you guys think of this?