Joe Atzberger wrote:
On Thu, Aug 27, 2009 at 4:25 PM, Edward M. Corrado
<ecorr...@ecorrado.us>wrote:
Nate Vack wrote:
On Thu, Aug 27, 2009 at 1:57 PM, Ryan
Ordway<rord...@oregonstate.edu> wrote:
$213,360 over 3 years
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.
Yeah -- but if you're looking only at storage costs, you'll
have an inaccurate estimate of your costs. You've got power,
cooling, sysadmin time, and replacements for failed disks. If
you want an apples-to-apples comparison, you'll want an
offsite mirror, as well.
I'm not saying S3 is always cost-effective -- but in our
experience, the costs of the disks themselves is dwarfed by
the costs of the related infrastructure.
I agree that the cost of storage is only one factor. I have
to wonder
though, how much more staff time do you need for local storage
than cloud storage? I don't know the answer but I'm not sure it
is much more than setting up S3 storage, especially if you have
a good partnership with your storage vendor.
Support relationships, especially regarding storage are very
costly. When I worked at a midsize datacenter, we implemented a
backup solution with STORServer and tivoli. Both hardware and
software were considerably costly. Initial and ongoing support,
while indispensable was basically as much as the cost of the
hardware every few years.
They can be depending on what you are doing and what choices on
software you make, but for long term preservation purposes they
don't have to be nearly as expensive as what Ryan calculated S3 to
cost. If you shop around you can get a quality 36GB array with 3 yr
warranty for say $30,000 that is almost $180,000 less than S3
(probably much less, I'm be less than generous with my Sun
discounts and only briefly looked at there prices). Even if we use
the double your cost for support, it is still over $50,000 a year
less for 3 years. Yes, we might need some expertise, but running a
36TB preservation storage array is not a $50,000 a year job and
besides, what is wrong with growing local expertise?
...
Yes, maybe you save on staff time patching software on your
storage array, but that is not a significant amount of time -
esp. since you are still going to have some local storage, and
there isn't much difference in staff time in doing 2 TB vs. 20
TB.
There's a real difference. I can get 2 TB in a single HDD, for
example this one for $200 at NewEgg:
http://www.newegg.com/Product/Product.aspx?Item=N82E16822148413
<http://www.newegg.com/Product/Product.aspx?Item=N82E16822148413>
Any high school kid can install that. 20 TB requires some kind
of additional structure and additional expertise.
Well building a 20 TB storage device and getting it to work can
actually be very cheap and doesn't require a PhD (just a local
GNU/Linux geek who likes to play with hardware) if you are OK with
a home grown solution. I wouldn't be satisfied with that, but I
don't see how a commercial offering that adds up to $150,000 worth
of expertise and infrastructure.
You may some time on the initial configuration, but you still
need to
configure cloud storage. Is cloud storage that much easier/less
time consuming to configure than an iSCSI device? Replacement
for disks would be covered under your warranty or support
contract (at least I would hope you would have one).
Warranties expire and force you into ill-timed, hardly-afforded
and dangerous-to-your-data upgrades. Sorta like some ILS systems
with which we are all familiar.
Yes some application upgrades can cause issues, but how is that
different if your application and/or storage is in a cloud?
The cloud doesn't necessarily stay the same, but the part you
care about (data in, data out) does.
How do you know they won't change their cloud models? And you don't
even have a warranty with the cloud. They won't even guarantee they
won't delete your data.
As long as you use a common standards based method of storage, you
won't have any more issues getting it to work than you will getting
future application servers to work with the cloud. While I'm not a
huge fan of NFS I've been using it for many years with no problems
due to changes in NFS or operating systems or hardware. NFS has
been available to the public for about 20 years. Occasionally you
may need to migrate it from one platform or one machine to another
but you very well need to do that with clouds as well. Maybe you
are using S3 but for whatever reason Sun gives you a better deal
with better terms and guarantees for using their cloud. Maybe
Amazon drops S3. Maybe because S3 moves servers to a country that
you are not legally allow to have your data in. Yes, you have to
plan for migration to new platforms but I fail to see how you don't
need to do that with the cloud. Really any major technological
decision should have an exit plan. Preservation storage is not
different in that and the cloud doesn't change that.
Edward
The power and cooling can be a savings, but in many cases the
library or individual departments don't pay for electricity, so
while *someone* pays the cost, it might not be the individual
department. Cooling and electricity costs are an actually a
great argument for tape for large-scale storage. Tape might
seem old fashioned, but in many applications it by far offers
the best value of long term storage per GB.
It's true, tape is still an worthwhile option. Alternatives like
optical or magneto-optical media just have not kept up.
Again, I'm not totally against the cloud and there are some
things I think
it could be very useful for, but the cloud doesn't make up for
the lack of (or just bad) planning.
Yeah, there's no system good enough to compensate for bad
planning and management. --Joe
