On Aug 27, 2009, at 6:22 AM, Rosalyn Metz wrote:
> Might I suggest you look into cloud computing services if you're  
> looking at
> different options. (I know you're all shocked I suggested it).  If our
> budget weren't so abysmal (and going to get worse) we would be using  
> it
> right now rather than the snap server we purchased with leftover  
> funds.  The
> benefits of using the cloud is of course the elasticity it offers  
> you.  The
> negative is that you have to pay to put your files into the cloud  
> and then
> pay again to take them out (and since we've already been slashed 30%  
> and are
> guaranteed another slash...that idea was shot down).


I did a rough cost analysis of S3 as an offsite archive of roughly  
20TB of data with estimated growth of between 6-8TB per year based on  
current growth rates. It ended up looking something like this:

$1.80 * 20000    storage
$2.04 * 20000    data transfer

$36,000 year 1 storage (20TB)
$40,800 year 1 data transfer (20TB)
$46,800 year 2 storage (26TB)
$12,240 year 2 data transfer (6TB)
$61,200 year 3 storage (34TB)
$16,320 year 3 data transfer (8TB)

$213,360 over 3 years

This only took into account storage and data transfer costs, and did  
not include READ/WRITE request costs.

Granted, this was awhile ago. I haven't checked to see if Amazon has  
changed any of their pricing or policies so this could be out of date.  
It looks like the data transfer cost could be avoided by shipping the  
data to them, although I don't know if they will do that for large  
amounts of data.

If you're ONLY looking at storage costs, SATA drives in enterprise  
RAID systems range from about $1.00/GB to about $1.25/GB for online  
storage. If you don't need immediate access to files, then nearline  
and offline storage is much cheaper. I can't find the exact figures,  
but LTO-4 tapes have a 800GB native / 1.6TB compressed capacity with a  
cost of something like $0.25/GB or something like that.

Also, don't rule out compression. The TIFF files that I was told were  
not compressable I was able to compress down from about 20TB to about  
4TB using bzip2 -9. It will require some intermediate decompression  
when someone needs to use them, but it's a lot less expensive to store  
4TB than 20TB. You could even decompress the files on-the-fly without  
too much effort.

Ryan

--
Ryan Ordway                           E-mail: [log in to unmask]
Unix Systems Administrator               [log in to unmask]
OSU Libraries, Corvallis, OR 97331    Office: Valley Library #4657