Robin,
From recollection the business case for investment in power protection
technology was relatively simple.
We calculated what the downtime per hour was worth and how frequently it
happened. We used to
have several if not more incidents per year and that would cause major
system outages. When you have
over 1000 staff and multiple remote sites depending on your data center
(now data centers, plural). Calculate
cost per hour for staff wages alone and it becomes quite easy to
justify. (I am not even going to fact in loss
of reputation and the media in this, or our most important customer. Our
students)
I cannot *stress* just how important power and environment protection is
to data. It is the main consideration
I take into account when deploying new sites. (This discussion went off
list yesterday and I was mentioning
these same things there). My analogy here is what would be the first
thing NASA designs into a new space craft?
Life Support. Without it you don't even leave the ground. Electricity
*is* the lifeblood of available storage.
Case in point. Last year we had an arsonist set fire to a critical point
in out campus infrastructure last year which burnt
down a building that just happened to have one of the main communication
and power trenches running
through it. Knocked out around 5 buildings on that campus for two weeks.
Immense upheaval and disruption
followed. Our brand new DR data center was on that site. Kept running
because of redundant fibre paths to
the SAN switches and core routers so that we could still provide service
to the rest of the campus and maintain
active DR to our primary site. Emergency power via generator was also
available until main power could be rerouted
to the data center as well.
I will take a look at the twinstrata website. (as should others).
Sorry to all if we are diverging too much from zfs-discuss.
/Scott
This stuff does happen. When you have been around for a while you see it.
Robin Harris wrote:
Calculating the availability and economic trade-offs of configurations
is hard. Rule of thumb seems to rule.
I recently profiled an availability/reliability tool
on StorageMojo.com that uses Bayesian analysis to estimate datacenter
availability. You can quickly (minutes, not days) model systems and
compare availability and recovery times as well as OpEx and CapEx
implications.
One hole: AFAIK, ZFS isn't in their product catalog. There's a free
version of the tool at http://www.twinstrata.com/
Feedback on the tool from this group is invited.
Robin
StorageMojo.com
Date: Tue, 17 Feb 2009 21:36:38 -0800
From: Richard Elling <richard.ell...@gmail.com
<mailto:richard.ell...@gmail.com>>
To: Toby Thain <t...@telegraphics.com.au
<mailto:t...@telegraphics.com.au>>
Cc: zfs-discuss@opensolaris.org <mailto:zfs-discuss@opensolaris.org>
Subject: Re: [zfs-discuss] ZFS on SAN?
Message-ID: <499b9e66.2010...@gmail.com
<mailto:499b9e66.2010...@gmail.com>>
Content-Type: text/plain; charset=ISO-8859-1; format=flowed
Toby Thain wrote:
Not at all. You've convinced me. Your servers will never, ever lose
power unexpectedly.
Methinks living in Auckland has something to do with that :-)
http://en.wikipedia.org/wiki/1998_Auckland_power_crisis
When services are reliable, then complacency brings risk.
My favorite example recently is the levees in New Orleans.
Katrina didn't top the levees, they were undermined.
-- richard
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Scott Lawson
Systems Architect
Manukau Institute of Technology
Information Communication Technology Services Private Bag 94006 Manukau
City Auckland New Zealand
Phone : +64 09 968 7611
Fax : +64 09 968 7641
Mobile : +64 27 568 7611
mailto:sc...@manukau.ac.nz
http://www.manukau.ac.nz
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$i=pack(c5,(41*2),sqrt(7056),(unpack(c,H)-2),oct(115),10);'
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