What a load of ********.

On 30/05/2017 08:03, harry wrote:
What a load of ********.

OK a power surge 'could' take out one data centre, but as they have
class 3 independent power feeds - never been known.
They have huge battery backup which keeps all running while own
generators run up.


However how would it take out other data centres as the newtork would be
dual redundant in Geographically remote locations.


Be interesting to see what comes out of this.

On 30/05/17 08:20, rick wrote:
On 30/05/2017 08:03, harry wrote:
What a load of ********.

OK a power surge 'could' take out one data centre, but as they have
class 3 independent power feeds - never been known.
They have huge battery backup which keeps all running while own
generators run up.


However how would it take out other data centres as the newtork would be
dual redundant in Geographically remote locations.


Be interesting to see what comes out of this.

crap design by incompetent yes men in middle management


--
"If you dont read the news paper, you are un-informed. If you read the
news paper, you are mis-informed."

Mark Twain

On 30/05/2017 08:38, The Natural Philosopher wrote:
On 30/05/17 08:20, rick wrote:
On 30/05/2017 08:03, harry wrote:
What a load of ********.

OK a power surge 'could' take out one data centre, but as they have
class 3 independent power feeds - never been known.
They have huge battery backup which keeps all running while own
generators run up.

However how would it take out other data centres as the newtork would
be dual redundant in Geographically remote locations.

It appears that for some reason it took out everything including their
phone system and that it took almost forever to get it going again. Way
longer than you would expect for any PLC recovery plan. Something went
badly wrong - last remaining sysyop wizard away for the Bank Holiday?

Be interesting to see what comes out of this.

crap design by incompetent yes men in middle management

Possibly, or more likely I think that they made redundant all the people
who actually knew how things worked and how to maintain it.

The system might well have been OK if it had been maintained and
rebooted by people who actually knew what they were doing.

--
Regards,
Martin Brown

In article , Martin Brown '''newspam'''@nezumi
..demon.co.uk scribeth thus
On 30/05/2017 08:38, The Natural Philosopher wrote:
On 30/05/17 08:20, rick wrote:
On 30/05/2017 08:03, harry wrote:
What a load of ********.

OK a power surge 'could' take out one data centre, but as they have
class 3 independent power feeds - never been known.
They have huge battery backup which keeps all running while own
generators run up.

However how would it take out other data centres as the newtork would
be dual redundant in Geographically remote locations.

It appears that for some reason it took out everything including their
phone system and that it took almost forever to get it going again. Way
longer than you would expect for any PLC recovery plan. Something went
badly wrong - last remaining sysyop wizard away for the Bank Holiday?

Be interesting to see what comes out of this.

crap design by incompetent yes men in middle management

Possibly, or more likely I think that they made redundant all the people
who actually knew how things worked and how to maintain it.

The system might well have been OK if it had been maintained and
rebooted by people who actually knew what they were doing.



Indeed but since when has senior "management" ever known anything about IT?.


--
Tony Sayer

In article ,
says...


However how would it take out other data centres as the newtork would be
dual redundant in Geographically remote locations.


Its been suggested over at uk.railway that:

"BA appear to have both their main data centres on the same industrial
site near Heathrow. Presumably both on the same mains distribution feed!"

That would make sense to an airline, wouldn't it? After all, you wouldn't
have the co-pilot flying in a different plane to the pilot, would you?

--

Terry

---
This email has been checked for viruses by Avast antivirus software.
https://www.avast.com/antivirus

On 30/05/17 10:50, Terry Casey wrote:
In article ,
says...


However how would it take out other data centres as the newtork would be
dual redundant in Geographically remote locations.


Its been suggested over at uk.railway that:

"BA appear to have both their main data centres on the same industrial
site near Heathrow. Presumably both on the same mains distribution feed!"

That would make sense to an airline, wouldn't it? After all, you wouldn't
have the co-pilot flying in a different plane to the pilot, would you?

Sigh. Its seems that 'power surge' = We powercyled the kit, like what
you do with Windows and Netgear innit? and it didn't all come up and
play nice.

--
"I guess a rattlesnake ain't risponsible fer bein' a rattlesnake, but ah
puts mah heel on um jess the same if'n I catches him around mah chillun".

In article , The Natural Philosopher
wrote:
On 30/05/17 10:50, Terry Casey wrote:
In article ,
says...


However how would it take out other data centres as the newtork would
be dual redundant in Geographically remote locations.


Its been suggested over at uk.railway that:

"BA appear to have both their main data centres on the same industrial
site near Heathrow. Presumably both on the same mains distribution
feed!"

That would make sense to an airline, wouldn't it? After all, you
wouldn't have the co-pilot flying in a different plane to the pilot,
would you?

Sigh. Its seems that 'power surge' = We powercyled the kit, like what
you do with Windows and Netgear innit? and it didn't all come up and
play nice.

I suffered a "power surge" at home 2 weeks ago. One of my computers
started emitting magic smoke.

--
from KT24 in Surrey, England

On 30-May-17 8:54 AM, Martin Brown wrote:
....
The system might well have been OK if it had been maintained and
rebooted by people who actually knew what they were doing.

From what was being said last night, it might have been OK if somebody
had thought to check whether the backup system actually worked when needed.

--
--

Colin Bignell

In article ,
tony sayer wrote:
Possibly, or more likely I think that they made redundant all the
people who actually knew how things worked and how to maintain it.

The system might well have been OK if it had been maintained and
rebooted by people who actually knew what they were doing.



Indeed but since when has senior "management" ever known anything about IT?.

They apparently know enough about it to decide it will be better out
sourced to India. Hope the penalties etc they have to pay after this
fiasco shows them a headline cost may not always be the true one.

--
*Ham and Eggs: Just a day's work for a chicken, but a lifetime commitment

Dave Plowman London SW
To e-mail, change noise into sound.

On Tue, 30 May 2017 11:08:36 +0100, Nightjar wrote:

From what was being said last night, it might have been OK if somebody
had thought to check whether the backup system actually worked when
needed.

Wouldn't be the first time (or the last) that the "regulary tested"
backup generator fails to start (or the auto start system doesn't) or
if it does start falls over within minutes.

Reasons:
It takes a brave man to truely simulate a mains failure by opening
the breaker on the incoming supply(s) without warning or any
preparation of down stream systems(*). It's "safer" to leave the
supply(s) connected, press "start" on the generator and when warmed
and up to speed, manually operate the changeover, run on generator
for a cuple of mins manually drop back to the supplies (that have
never been isolated) and shutdown generator. How many things
*doesn't* that test?

(*) One assumes BA would have doubley rendundant, hot spare, core
systems, so "just in case" you make sure that the breaker(s) you are
about to pull are only feeding the "non-live" core system.

What ever it was I've seen one report that there had to be some
"hardware changes", followed by databases being out of sync with each
other. A few hours ought to sort the hardware, what really screws you
up is bad/missing/mismatched data.

--
Cheers
Dave.

On 30/05/17 11:17, Dave Plowman (News) wrote:
In article ,
tony sayer wrote:
Possibly, or more likely I think that they made redundant all the
people who actually knew how things worked and how to maintain it.

The system might well have been OK if it had been maintained and
rebooted by people who actually knew what they were doing.



Indeed but since when has senior "management" ever known anything about IT?.

They apparently know enough about it to decide it will be better out
sourced to India. Hope the penalties etc they have to pay after this
fiasco shows them a headline cost may not always be the true one.



Some years ago, in the early 80s, I was in Pakistan on Business. I was
doing some equipment trials. I decided to test the equipment in the
hotel room. I was in a major city. I had a simple linear power supply
which 'dropped' the mains voltage to that required for the equipment.
The equipment itself would normally work over a wide range of input
voltages but it wouldn't power up correctly.

Out came the multimeter and at first it looked like the power supply had
failed. However, it turned out the mains voltage was way below the
supposed 240V, as I recall something under 200V. I spoke to our local
rep and it seems this was far from unusual- as were power cuts etc. This
was in a major city. Sure enough, that night when I needed to answer a
'call of nature', there was no power. The next morning, the mains
measured 265V.

Across the road, they were building another hotel. The scaffolding was
all made of bamboo. The hotel was already up to about 10 floors. The
workman were climbing it in bare feet, no hard hats or any safety kit to
be seen.

On Tue, 30 May 2017 08:23:34 +0100, Chris Hogg wrote:

PS: what exactly is a 'power surge' on the grid, and how's it
caused?

Good question, and not one that seems to have been answered so far.

On 30/05/2017 12:47, mechanic wrote:
On Tue, 30 May 2017 08:23:34 +0100, Chris Hogg wrote:

PS: what exactly is a 'power surge' on the grid, and how's it
caused?

Good question, and not one that seems to have been answered so far.

The ones I have seen were direct lightning strikes to the metal roof or
nearby electric pylons. In both cases damage was done to kit that was
notionally protected by heavy duty industrial grade surge arresters.

The worst one vaporised the telephone lines in reception leaving a 4"
wide charred mess down the wall and a dazed unconsolable receptionist.
Took days to get the line mended and the phone switchboard was toast.
That was after a strike to the metal roof of the building.

It was notable how getting one mainframe back online was made more
difficult by multiple systems failures in different zones. Normal CPU
failures usually are single point and neighbouring bits whereas a big
lightning strike seems to find perverse and unusual destructive paths.
Sacrificial protection bits somehow manages to save themselves at the
expense of parts that are much harder to access and replace.

However, BA don't seem to be claiming that it was from a lightning
strike but a "Power surge". Presumably they can back up their claim of
power surge by peak voltage/current spike detection and logging...

--
Regards,
Martin Brown

In article ,
Brian Reay wrote:
On 30/05/17 11:17, Dave Plowman (News) wrote:
In article ,
tony sayer wrote:
Possibly, or more likely I think that they made redundant all the
people who actually knew how things worked and how to maintain it.

The system might well have been OK if it had been maintained and
rebooted by people who actually knew what they were doing.



Indeed but since when has senior "management" ever known anything about IT?.

They apparently know enough about it to decide it will be better out
sourced to India. Hope the penalties etc they have to pay after this
fiasco shows them a headline cost may not always be the true one.



Some years ago, in the early 80s, I was in Pakistan on Business. I was
doing some equipment trials. I decided to test the equipment in the
hotel room. I was in a major city. I had a simple linear power supply
which 'dropped' the mains voltage to that required for the equipment.
The equipment itself would normally work over a wide range of input
voltages but it wouldn't power up correctly.

Must admit I'd thought the actual hardware would still be in the UK? But
under the control of their newly out sourced experts? Who might just have
a problem popping down the corridor to press the reset button in event of
a failure?

--
*No husband has ever been shot while doing the dishes *

Dave Plowman London SW
To e-mail, change noise into sound.

On Tue, 30 May 2017 10:59:57 +0100, charles wrote:

In article , The Natural Philosopher
wrote:
On 30/05/17 10:50, Terry Casey wrote:
In article ,
says...


However how would it take out other data centres as the newtork
would be dual redundant in Geographically remote locations.


Its been suggested over at uk.railway that:

"BA appear to have both their main data centres on the same
industrial site near Heathrow. Presumably both on the same mains
distribution feed!"

That would make sense to an airline, wouldn't it? After all, you
wouldn't have the co-pilot flying in a different plane to the pilot,
would you?

Sigh. Its seems that 'power surge' = We powercyled the kit, like what
you do with Windows and Netgear innit? and it didn't all come up and
play nice.

I suffered a "power surge" at home 2 weeks ago. One of my computers
started emitting magic smoke.

That's why I have three UPS units.



--
My posts are my copyright and if @diy_forums or Home Owners' Hub
wish to copy them they can pay me £1 a message.
Use the BIG mirror service in the UK: http://www.mirrorservice.org
*lightning surge protection* - a w_tom conductor

"Chris Hogg" wrote in message
...

PS: what exactly is a 'power surge' on the grid, and how's it caused?

The power surge quote was courtesy of Alex Cruz, BA CEO.

The same Alex Cruz who, after a total breakdown of BA's IT
systems caused a suspension of all the airlines services
worldwide for around 24 hours, was quoted as saying

"We would never compromise the integrity and security of our IT systems"

Which does make you wonder how much worse things could have been, if that
had been his intention all along


michael adams

....

On 30/05/2017 13:20, Tim Streater wrote:
In article , Martin Brown
wrote:

That was after a strike to the metal roof of the building.

No lighting conductors?

There were but they didn't seem to help. There was even a supergrid
pylon much taller and less than 100m away but it still hit our roof.

But the building to building potential difference also did a lot of
damage as only one was struck. You can't really do much about that since
all the current has to go somewhere when it reaches the ground.

--
Regards,
Martin Brown

In article ,
Martin Brown writes:
On 30/05/2017 12:47, mechanic wrote:
On Tue, 30 May 2017 08:23:34 +0100, Chris Hogg wrote:

PS: what exactly is a 'power surge' on the grid, and how's it
caused?

Good question, and not one that seems to have been answered so far.

The ones I have seen were direct lightning strikes to the metal roof or
nearby electric pylons. In both cases damage was done to kit that was
notionally protected by heavy duty industrial grade surge arresters.

The worst one vaporised the telephone lines in reception leaving a 4"
wide charred mess down the wall and a dazed unconsolable receptionist.
Took days to get the line mended and the phone switchboard was toast.
That was after a strike to the metal roof of the building.

It was notable how getting one mainframe back online was made more
difficult by multiple systems failures in different zones. Normal CPU
failures usually are single point and neighbouring bits whereas a big
lightning strike seems to find perverse and unusual destructive paths.
Sacrificial protection bits somehow manages to save themselves at the
expense of parts that are much harder to access and replace.

However, BA don't seem to be claiming that it was from a lightning
strike but a "Power surge". Presumably they can back up their claim of
power surge by peak voltage/current spike detection and logging...

One cause can be a disconnected neutral, which causes the voltage
on the least loaded phase to rise (and the most loaded phase to
drop). Worse case, that gets you ~400V. That could destroy the
input stage of a switched mode PSU designed for 240VAC.

About 17 years ago, there was a power surge at home, which did
for the ethernet port on an Sun Ultra 5 workstation. I don't
know the nature of it, but it was due to a high voltage fault
and the electricity company instantly offered to get the computer
repaired. In the event, my employer just gave me another one and
I don't think they bothered claiming back from Southern Electric.

--
Andrew Gabriel
[email address is not usable -- followup in the newsgroup]

On 5/30/2017 12:15 PM, Dave Liquorice wrote:
On Tue, 30 May 2017 11:08:36 +0100, Nightjar wrote:

From what was being said last night, it might have been OK if somebody
had thought to check whether the backup system actually worked when
needed.

Wouldn't be the first time (or the last) that the "regulary tested"
backup generator fails to start (or the auto start system doesn't) or
if it does start falls over within minutes.

Reasons:
It takes a brave man to truely simulate a mains failure by opening
the breaker on the incoming supply(s) without warning or any
preparation of down stream systems(*). It's "safer" to leave the
supply(s) connected, press "start" on the generator and when warmed
and up to speed, manually operate the changeover, run on generator
for a cuple of mins manually drop back to the supplies (that have
never been isolated) and shutdown generator. How many things
*doesn't* that test?

(*) One assumes BA would have doubley rendundant, hot spare, core
systems, so "just in case" you make sure that the breaker(s) you are
about to pull are only feeding the "non-live" core system.

What ever it was I've seen one report that there had to be some
"hardware changes", followed by databases being out of sync with each
other. A few hours ought to sort the hardware, what really screws you
up is bad/missing/mismatched data.

My thoughts too

On 5/30/2017 3:12 PM, Chris Hogg wrote:
On Tue, 30 May 2017 13:20:46 +0100, Tim Streater
wrote:

In article , Martin Brown
wrote:

That was after a strike to the metal roof of the building.

No lighting conductors?

AIUI a lightning conductor's primary purpose is not to conduct the
lightning strike to earth, but to discharge the cloud above it in an
attempt to stop the lightning in the first place. I believe there's a
significant current flowing in a lightning conductor some time before
a strike happens. If there is a lightning flash, it means the
conductor has failed in its primary purpose.

But I can't believe that's why lightning conductors were used in the
beginning; they must have been actually intended to conduct the
lightning and prevent damage to the church tower or whatever, even if
in those days no-one realised the true action.

Two good points.

On Tue, 30 May 2017 12:26:56 +0100, Tim Streater wrote:

I suffered a "power surge" at home 2 weeks ago. One of my
computers
started emitting magic smoke.

I've had that, more of "melt-down" though. Tower case mother board on
edge, for some unknown reason CPU power regulators got so hot they
slid down the board...

So why haven't you got a UPS? It's not as if a small APC costs very
much. Something like this:

https://www.amazon.co.uk/APC-Back-UP...-BE700G-UK/dp/
B002RXED6A/

I'm reasonably sure that will an "off-line" UPS. ie the mains is
normally fed straight through or via a simple 1:1 transformer with a
bit of filtering. Not sure if the Back-UPS models can also boost/buck
the mains via altering transformer taps, might be a Smart-UPS
feature. The invertor side only fires up to provide power when the
mains fails.

An "on-line" UPS powers the kit via the batteries and invertor secion
all the time. The incoming mains just feeds a hefty charger with
enough umph to charge the batteries whilst they are being drained by
the invertor.

Only an on-line UPS truely separates the suported kit from the mains.

--
Cheers
Dave.

On Tuesday, 30 May 2017 12:16:02 UTC+1, Dave Liquorice wrote:
On Tue, 30 May 2017 11:08:36 +0100, Nightjar wrote:

From what was being said last night, it might have been OK if somebody
had thought to check whether the backup system actually worked when
needed.

Wouldn't be the first time (or the last) that the "regulary tested"
backup generator fails to start (or the auto start system doesn't) or
if it does start falls over within minutes.

Reasons:
It takes a brave man to truely simulate a mains failure by opening
the breaker on the incoming supply(s) without warning or any
preparation of down stream systems(*). It's "safer" to leave the


It's donr once a month at UK hospitals.

On 30/05/17 12:18, Brian Reay wrote:

Across the road, they were building another hotel. The scaffolding was
all made of bamboo. The hotel was already up to about 10 floors. The
workman were climbing it in bare feet, no hard hats or any safety kit to
be seen.

I read somewhere that bamboo makes first class scaffolding. In Hong Kong
they build skyscrapers with it.

Agree with the rest of what you say though.

Another Dave

--
Change nospam to techie

On 5/30/2017 4:16 PM, Another Dave wrote:
On 30/05/17 12:18, Brian Reay wrote:

Across the road, they were building another hotel. The scaffolding was
all made of bamboo. The hotel was already up to about 10 floors. The
workman were climbing it in bare feet, no hard hats or any safety kit
to be seen.

I read somewhere that bamboo makes first class scaffolding. In Hong Kong
they build skyscrapers with it.


Plus:

Strong, light, tough, flexible (so it shares load well), remains elastic
at high bending strains.

Minus:

More difficult to join (I believe it is normally tied rather than clamped)

In article , Tim Streater
wrote:
In article , charles
wrote:

In article , The Natural Philosopher
wrote:
On 30/05/17 10:50, Terry Casey wrote:
In article ,
says...

However how would it take out other data centres as the newtork
would be dual redundant in Geographically remote locations.

Its been suggested over at uk.railway that:

"BA appear to have both their main data centres on the same
industrial site near Heathrow. Presumably both on the same mains
distribution feed!"

That would make sense to an airline, wouldn't it? After all, you
wouldn't have the co-pilot flying in a different plane to the pilot,
would you?

Sigh. Its seems that 'power surge' = We powercyled the kit, like what
you do with Windows and Netgear innit? and it didn't all come up and
play nice.

I suffered a "power surge" at home 2 weeks ago. One of my computers
started emitting magic smoke.

So why haven't you got a UPS?

I was using a UPS - its output "surged".

--
from KT24 in Surrey, England

In article ,
Another Dave wrote:
On 30/05/17 12:18, Brian Reay wrote:

Across the road, they were building another hotel. The scaffolding was
all made of bamboo. The hotel was already up to about 10 floors. The
workman were climbing it in bare feet, no hard hats or any safety kit
to be seen.

I read somewhere that bamboo makes first class scaffolding. In Hong Kong
they build skyscrapers with it.


20 years ago, in Lithuania, they were using larch poles. Any metal scaff
tended to "walk" overnight.


--
from KT24 in Surrey, England

In article ,
Terry Casey scribeth thus
In article ,
says...


However how would it take out other data centres as the newtork would be
dual redundant in Geographically remote locations.


Its been suggested over at uk.railway that:

"BA appear to have both their main data centres on the same industrial
site near Heathrow. Presumably both on the same mains distribution feed!"

That would make sense to an airline, wouldn't it? After all, you wouldn't
have the co-pilot flying in a different plane to the pilot, would you?


LOL!....


I Often wonder about this dual mains feed in a data centre after all
where do they manage to get two separate off differing transformers from
and differing HV feeds?.


Unless someone has the idea that different phases are different feeds?..

--
Tony Sayer

Some years ago, in the early 80s, I was in Pakistan on Business. I was
doing some equipment trials. I decided to test the equipment in the
hotel room. I was in a major city. I had a simple linear power supply
which 'dropped' the mains voltage to that required for the equipment.
The equipment itself would normally work over a wide range of input
voltages but it wouldn't power up correctly.

Out came the multimeter and at first it looked like the power supply had
failed. However, it turned out the mains voltage was way below the
supposed 240V, as I recall something under 200V. I spoke to our local
rep and it seems this was far from unusual- as were power cuts etc. This
was in a major city. Sure enough, that night when I needed to answer a
'call of nature', there was no power. The next morning, the mains
measured 265V.


Mind you some SMPS's do cope with a very wide mains input variation
these days..


Across the road, they were building another hotel. The scaffolding was
all made of bamboo. The hotel was already up to about 10 floors. The
workman were climbing it in bare feet, no hard hats or any safety kit to
be seen.




Standard practice there..

--
Tony Sayer

In article , Martin Brown '''newspam'''@ne
zumi.demon.co.uk scribeth thus
On 30/05/2017 12:47, mechanic wrote:
On Tue, 30 May 2017 08:23:34 +0100, Chris Hogg wrote:

PS: what exactly is a 'power surge' on the grid, and how's it
caused?

Good question, and not one that seems to have been answered so far.

The ones I have seen were direct lightning strikes to the metal roof or
nearby electric pylons. In both cases damage was done to kit that was
notionally protected by heavy duty industrial grade surge arresters.

The worst one vaporised the telephone lines in reception leaving a 4"
wide charred mess down the wall and a dazed unconsolable receptionist.
Took days to get the line mended and the phone switchboard was toast.
That was after a strike to the metal roof of the building.

It was notable how getting one mainframe back online was made more
difficult by multiple systems failures in different zones. Normal CPU
failures usually are single point and neighbouring bits whereas a big
lightning strike seems to find perverse and unusual destructive paths.
Sacrificial protection bits somehow manages to save themselves at the
expense of parts that are much harder to access and replace.

However, BA don't seem to be claiming that it was from a lightning
strike but a "Power surge". Presumably they can back up their claim of
power surge by peak voltage/current spike detection and logging...


Well broadcast site's do cope very well but they are well protected agin
Jove's bolts.

Wasn't there a lot of lighting around the channel area on Friday
night?..
--
Tony Sayer

In article , Chris Hogg
scribeth thus
On Tue, 30 May 2017 13:20:46 +0100, Tim Streater
wrote:

In article , Martin Brown
wrote:

That was after a strike to the metal roof of the building.

No lighting conductors?

AIUI a lightning conductor's primary purpose is not to conduct the
lightning strike to earth, but to discharge the cloud above it in an
attempt to stop the lightning in the first place. I believe there's a
significant current flowing in a lightning conductor some time before
a strike happens. If there is a lightning flash, it means the
conductor has failed in its primary purpose.

But I can't believe that's why lightning conductors were used in the
beginning; they must have been actually intended to conduct the
lightning and prevent damage to the church tower or whatever, even if
in those days no-one realised the true action.


The idea is to "shunt" the discharge around whatever it is your trying
to protect.

Messers Furse & Co did a very good online book on the subject once..
--
Tony Sayer

En el artÃ*culo , Martin Brown '''newspam''
escribió:

However, BA don't seem to be claiming that it was from a lightning
strike but a "Power surge". Presumably they can back up their claim of
power surge by peak voltage/current spike detection and logging...

Report on the so-called "power surge" in the Grauniad:

https://www.theguardian.com/business...sh-airways-it-
failure-experts-doubt-power-surge-claim

"Experts have questioned British Airways claim that this weekend's
catastrophic IT failure was down to a 'power surge', as the company's
chief executive has claimed"

I was sceptical from the word go. Cruz is probably more familiar with
cashing in his stock options and awarding himself fat bonuses than the
subtleties of running a data centre.

--
(\_/)
(='.'=) "Between two evils, I always pick
(")_(") the one I never tried before." - Mae West

On Tue, 30 May 2017 18:31:19 +0100, tony sayer wrote:

I Often wonder about this dual mains feed in a data centre after all
where do they manage to get two separate off differing transformers from
and differing HV feeds?.

Give enough money to your local DNO and they will provide diversity
power.

Something like BA's data centre I'd expect to have at least two
diversly routed 11 kV feeds from different Primary subsations (33 kV
11 kV) that don't share a main 33 kV supply or the backups to those 33 kV (might be 11 kV, our local Primary has 11 kV backup).

There are documents on the web that decribe the power arrangements
for football stadiums, that may host the larger competitions. Search
for "fifa lighting power supply"

--
Cheers
Dave.

On 30/05/2017 08:23, Chris Hogg wrote:
On Tue, 30 May 2017 00:03:03 -0700 (PDT), harry
wrote:

What a load of ********.

I expect the sun suddenly came out from behind a cloud, thousands of
solar panels suddenly started pumping out squillions of watts and the
grid didn't react quickly enough. Expect lots more in the future.

;-)

PS: what exactly is a 'power surge' on the grid, and how's it caused?

Maybe a toe-rag stealing the surge protection gear from the substation.

--
Max Demian

On 5/30/2017 7:58 PM, Chris Hogg wrote:
On Tue, 30 May 2017 19:38:52 +0100, Max Demian
wrote:


PS: what exactly is a 'power surge' on the grid, and how's it caused?

Maybe a toe-rag stealing the surge protection gear from the substation.

From the replies, it seems that a power surge is a nothing more than
very short duration voltage spike caused by a lightning strike. I had
wondered if that was all it was, or whether some massive bit of
electrical gear like a carbon-arc furnace in a steel works suddenly
shutting down might cause it, but as no-one mentioned anything like
that, I guess I'm wrong.

Steel works! We are talking about the home counties :-)

In article ,
tony sayer wrote:
In article ,
Terry Casey scribeth thus
In article ,
says...


However how would it take out other data centres as the newtork would be
dual redundant in Geographically remote locations.


Its been suggested over at uk.railway that:

"BA appear to have both their main data centres on the same industrial
site near Heathrow. Presumably both on the same mains distribution feed!"

That would make sense to an airline, wouldn't it? After all, you wouldn't
have the co-pilot flying in a different plane to the pilot, would you?


LOL!....


I Often wonder about this dual mains feed in a data centre after all
where do they manage to get two separate off differing transformers from
and differing HV feeds?.

When BBC TV Centre was built, it was on the West London 33kV ring. it also
had a reserve feed direct from Battersea. "It will be fine as long as
Battersea doesn't blow up" - which, of course it did - well the main power
board at any rate (April 1964)

--
from KT24 in Surrey, England

On 30/05/2017 13:31, Dave Plowman (News) wrote:
In article ,
Brian Reay wrote:
On 30/05/17 11:17, Dave Plowman (News) wrote:
In article ,
tony sayer wrote:
Possibly, or more likely I think that they made redundant all the
people who actually knew how things worked and how to maintain it.

The system might well have been OK if it had been maintained and
rebooted by people who actually knew what they were doing.



Indeed but since when has senior "management" ever known anything about IT?.

They apparently know enough about it to decide it will be better out
sourced to India. Hope the penalties etc they have to pay after this
fiasco shows them a headline cost may not always be the true one.



Some years ago, in the early 80s, I was in Pakistan on Business. I was
doing some equipment trials. I decided to test the equipment in the
hotel room. I was in a major city. I had a simple linear power supply
which 'dropped' the mains voltage to that required for the equipment.
The equipment itself would normally work over a wide range of input
voltages but it wouldn't power up correctly.

Must admit I'd thought the actual hardware would still be in the UK? But
under the control of their newly out sourced experts? Who might just have
a problem popping down the corridor to press the reset button in event of
a failure?

You don't need a reset button, proper servers can by powered up or down
over a separate, independent network connection. This is independent of
the rest of the server, so it not affected by the system being locked up
by a crash. They can even have their operating systems installed from
scratch remotely. A person only needs to be there if a physical item
such as a hard-disk or fan needs replacing.

The network itself should be designed so that it automatically restarts
after power loss or consists of devices that can be remotely restarted
in sequence 'til the full network is up and running.

SteveW

On 30/05/2017 18:32, tony sayer wrote:

Some years ago, in the early 80s, I was in Pakistan on Business. I was
doing some equipment trials. I decided to test the equipment in the
hotel room. I was in a major city. I had a simple linear power supply
which 'dropped' the mains voltage to that required for the equipment.
The equipment itself would normally work over a wide range of input
voltages but it wouldn't power up correctly.

Out came the multimeter and at first it looked like the power supply had
failed. However, it turned out the mains voltage was way below the
supposed 240V, as I recall something under 200V. I spoke to our local
rep and it seems this was far from unusual- as were power cuts etc. This
was in a major city. Sure enough, that night when I needed to answer a
'call of nature', there was no power. The next morning, the mains
measured 265V.


Mind you some SMPS's do cope with a very wide mains input variation
these days..

Some, well designed, linear ones did as well. I remember using a
14-track reel-to-reel tape recorder to record vibrations for later
analysis 30-odd years ago. That recorder would run off anything from 24V
to 400V, a.c. or d.c.

SteveW

On 30/05/2017 10:55, The Natural Philosopher wrote:
On 30/05/17 10:50, Terry Casey wrote:
In article ,

says...


However how would it take out other data centres as the newtork would be
dual redundant in Geographically remote locations.


Its been suggested over at uk.railway that:

"BA appear to have both their main data centres on the same industrial
site near Heathrow. Presumably both on the same mains distribution
feed!"

That would make sense to an airline, wouldn't it? After all, you wouldn't
have the co-pilot flying in a different plane to the pilot, would you?

Sigh. Its seems that 'power surge' = We powercyled the kit, like what
you do with Windows and Netgear innit? and it didn't all come up and
play nice.

Which shouldn't have mattered. The guy from Ryanair was on the radio
yesterday saying that they have a primary and two backup datacentres,
with automatic failover. All at completely different locations.

Surely BA should have similar? And without the primary coming back up
properly, one of the backup datacentres should have kept everything
running as normal.

SteveW

In article l.net,
Dave Liquorice scribeth thus
On Tue, 30 May 2017 18:31:19 +0100, tony sayer wrote:

I Often wonder about this dual mains feed in a data centre after all
where do they manage to get two separate off differing transformers from
and differing HV feeds?.

Give enough money to your local DNO and they will provide diversity
power.


Yes If you do have deep and very deep pockets! A backup diseasel is
cheaper im most all cases.

Something like BA's data centre I'd expect to have at least two
diversly routed 11 kV feeds from different Primary subsations (33 kV
11 kV) that don't share a main 33 kV supply or the backups to those 33 kV
(might be 11 kV, our local Primary has 11 kV backup).


Well had this debate with a friend who works in data centres and he
reckons that not many have that luxury - one went down near that London
Telehouse a while ago only had the one mains feed as there wasn't
another available for quite some distance.

Decent UPS batteries and a well tested and fuelled diesel and the hope
of course that BT's fibre plant is on some reserve power too;!

What to hear that one where so BT term box wasn't on a backed up supply
to a data centre ,just got overlooked..

There are documents on the web that decribe the power arrangements
for football stadiums, that may host the larger competitions. Search
for "fifa lighting power supply"

Yes mainly to do with lighting for TV and yes if you do have two
separate mains supplies nice, and the diesel genny not a lot of money
for a Footie club a weeks wages for a player perhaps;!.

--
Tony Sayer