>> I would have thought that needing more disk space is such a crushingly
>> rare event that it makes almost no sense to optimise for it.
>
> No it's not. You may need to run an app in debug mode for a while and
> need extra space to store the dumps. You may run into seasonal peeks and
> need extra storage just for that period. Etc... Sizing hundreds of
> servers for a worst case scenario is not efficient use of the company's
> money. You are much better off having some amount of slack space that
> you can swing around when needed.

Maybe that's the problem. I cannot imagine any task that would ever 
require "hundreds of servers". I'm struggling to think of a task that 
would require more than about a dozen at worst. I mean, unless you work 
for one of the largest companies on the planet, which almost nobody does.

>> If you have
>> to take a server offline once every 5 years to add another disk, that's
>> still 99.99% uptime.
>
> Not if your contract says "monthly uptime of 99.99%". ;-)

Mmm, good point.

>> You claimed that it's not insane to run a SAN over the Internet,
>
> When did I say that?

Francois Labreque wrote:
 > We've also had the performance discussion before.  Yes, the
 > theoretical access speed of a local SATA drive is much faster than
 > that of a SAN attached logical disk, but in actual real world
 > practice, with real world data, there's not much of a difference,
 > even on SANs located halfway across town in another building.

>>> most SAN implementations run dedicated protocols over
>>> fibre at Gbps speeds.
>>
>> It's news to me that such things even exist yet - but perhaps that was
>> your point?
>
> Actually, it shouldn't be news to you. We went over this in great
> details a few months ago. Remember my nice ascii-graphics chart with the
> servers, SAN switches, drive enclosures and tape units?

I don't remember much of the detail of that discussion - in particular, 
I don't recall there being any actual speed numbers involved. But still, 
as I say, it looks like I will get to see for myself shortly.

> Not that SANs are infaillible, but why do you assume that it will fail?

They want to back up 200GB of data per day over a 5 Mbit/sec Internet 
connection. You do the math.

Plus, since when does rolling out a brand new complex system go 
smoothly? ;-)

>> So what you're saying is that a handful of the richest companies on
>> Earth can afford to do this?
>
> There's more than a handful of companies who can afford it. A few £M in
> extra telco costs per year is nothing compared to the prospect of going
> out of business because your data centre had a 110-story building crash
> on top of it.

So you're saying that more than "a handful" of telco companies exist?

>> Yeah, I guess that'll be why I haven't seen it before. :-P
>
> I have never seen the Merryll-Lynch data centre first hand, either, but
> that isn't necessary to know that they were back up and running hours
> after the WTC towers fell... Reading the story of how they restarted
> their operations from their disaster recovery location was enough. Then
> the "Interesting...how'd they manage that?" questions popped up in my
> head, and I started digging...

My first question would have been "who is Merryll-Lynch?", but OK.

> Which is the main point of this whole discussion: reading the newspaper
> and other news-related web sites, once in a while, is not a bad thing,
> even if the event in question doesn't affect you directly, there may be
> bits of insight to be gathered.

Hmm. I'm now trying to remember how the hell we *got* to this topic in 
the first place... (Just look at that subject line!)

At any rate, I agree there certainly isn't anything /bad/ about reading 
news-related stuff. I just don't see how it is an absolutely mandatory 
requirement of being alive, that's all.

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