Le 2012-02-02 10:05, Invisible a écrit :
>> I don't understand why you somehow think one needs to actually work for
>> British Airways, Siemens, Yamaha or IBM to be able to imagine what's
>> it's like to work in a company with 100,000+ employees.
>
> It's like the thing with Google's data centre. A "computer" is a
> low-power device. Unless you've ever worked with thousands of them at
> once, it just doesn't occur to you what there might be power supply or
> cooling issues to overcome.
>
> I imagine the reverse also applies; somebody who works for Google would
> probably think that the solution to "our tape drive just died" is "so go
> buy a new one". They probably wouldn't even realise that to a small
> company, £3,000 for a new tape drive is actually /a crapload of money/.
> It probably wouldn't even occur to them.
>
> In short, you don't really understand what it's like to work within a
> given set of constraints unless, you know, you've had to work within
> that set of constraints...
>

Agreed.  When I have a $250,000* piece of equipment that fails, I call 
the toll-free number of the hardware vendor and they send me a 
replacement in less than 24 hours, meanwhile its redundant mate keeps 
the network running.  I don't have to deal with purchasing, maintenance 
contracts or any of that.

BUT - and that's the important part - I thanks the FSM every chance I 
get to not have to deal with these issues.  I've read too many horror 
stories in comp.dcom.sys.cisco of people who had mission-critical 
hardware fail and were asking for help trying to get the device back up 
while trying to convince management to buy a new one, or looking for 
spare parts on eBay.

*I assume that's how much these things cost as I have absolutely never 
had to use the $ key on my keyboard, unless I was programming in Perl.

>>> 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.
>>
>> "In another building" DOES NOT mean "over the Internet". Private data
>> circuits predate the internet, and no company would use the Internet to
>> link two data centres together.
>
> How is that even *possible*? It's not like you can just go to the
> hardware store and buy 25km of copper wire and then put it into the
> ground with a shovel on your day off or something...
>

You don't do it yourself, unless you are in a campus environment and can 
easily rip up the parking lot and lay down your own fibre or copper.

Step 1.  Call your telco rep and order a circuit between site A and site A.
Step 2.  Telco will forward the request to a planner who will determine 
if the existing cabling between both sites and central offices (CO) has 
enough available bandwidth.
Step 3a.  If not, the planner will forward the request to their 
infrastructure group who will get diging permits from the 
city/county/whatever and lay down new bundles of cables.
Step 3b.  If the answer is yes, or once the new cables have been laid, 
the telco planner will forward your request to an enabler who will 
configure the CO switches to map the circuit from Site A's demarcation 
point to Site B's demarcation point.
Step 4.  Technicians will come on site, at both locations, and terminate 
the circuit from their demarc point to the exact rack you ask them to.
Step 5.  You plug in the circuit in your equipment (router, switch, or 
mainframe front-end-processor, to name a few)

Tada!

Usually, all of this is done for a small nominal fee.  Any work they 
have to do between demarc points will be undertaken at their own 
expense, which they will recoup on your monthly usage bill, of course.

By the way, if you ordered an "internet" link, the exact same steps 
would have to take place, except that they would be duplicated for site 
A to ISP and ISP to site B, and then the ISP would add its own routers 
at both ends and charge you twice as much and more for the "managed 
services".

>>>> 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.
>>
>> So their backup strategy will fail. Not the actual SAN. Gotcha.
>
> Well, given that backup is what this SAN is *for*, I guess I mixed up
> the two things.
>

I thought the SAN would replace some of the servers' internal disks. Sorry.

>>> Plus, since when does rolling out a brand new complex system go
>>> smoothly? ;-)
>>
>> When it's planned properly. I've seen it happen. But, I must admit, that
>> I've seen quite a few disasters, too.
>
> Given the company that *I* work for, would you expect a smooth rollout? ;-)
>
>>> So you're saying that more than "a handful" of telco companies exist?
>>
>> There are, in fact, more than a handful of telcos in most countries.
>> while the actual wires underground usually belong to one or two
>> companies, the other ones will buy bandwidth from the
>> cable-owning-entity and resell it to other corporations. This is why,
>> for example, I can rent circuits from BT in Canada, even though they do
>> not own any of the fibre optics here.
>>
>> But this has nothing to do with the fact that I was talking about
>> businesses buying telecommunications services from the telcos, not the
>> telcos themselves. Last time I checked HSBC was not a telco, and I do
>> know that they've had 10Gbps links between their data centres for over
>> 10 years.
>
> OK, so a major /bank/ can also accord crazy technology. None of this
> alters the fact that the next tiny company I end up working for won't be
> able to afford this kind of thing.

What makes you think you can't find work in a large company?

-- 
/*Francois Labreque*/#local a=x+y;#local b=x+a;#local c=a+b;#macro P(F//
/*    flabreque    */L)polygon{5,F,F+z,L+z,L,F pigment{rgb 9}}#end union
/*        @        */{P(0,a)P(a,b)P(b,c)P(2*a,2*b)P(2*b,b+c)P(b+c,<2,3>)
/*   gmail.com     */}camera{orthographic location<6,1.25,-6>look_at a }

Post a reply to this message