Questions
Was the UPS repaired “in house” or from a contractor?
Was the repair cause of the issue?
Was the repair executed according to the approved repair policy?
Was the UPS in a previous approved state about battery pack age, temperature, ventilation and so on?
Capital question: will the technician be used as scapegoat from OVH or management will take responsibility and account on their budget about losses and service restore?
I know I work in datacenter, mainly they prefer to use inert gas and high fog (water under heavy pressure), the two are not destructive for humans and servers.
CO2 is not more used when you want to extinguish a room.
Hi
For the usually respectable FAZ, such a sentence is a bit “cheap”:
"Oft werden die Notstromaggregate vieler Rechenzentren mit Diesel betrieben. ".
English: “Often, emergency power generators run on diesel”.
Not only in data centers, but hospitals, airports or almost anything equipped with an emergency power generator uses Diesel. Worldwide…
I haven’t seen a Gas Emergency Power station in any catalog, let alone a nuclear powered one!
Diesel powers more than 99.9% of all emergency power supplys - worldwide!
In 2010, they put in two big generators in a new hospital in Switzerland. The generators were in the celler - rather a big underground cavern, as the generators were more than a story high!
8 Months or so later, the area was flodded, and power cut of.
The architects and engineers never thought that a flood could be the cause of a power outage, and so the generators - with their diesel motors were under water. Very difficult to start a motor when the air intake is under water…
Really stupid!
In Zurich, there’s an old private bank, in an old building. The whole IT is on the fifth and top floor…
Why? The closest Dam to Zürich is the Sihlsee, an artificially dammed lake to create electricity. The bank people calculatde the flash flood, should the Dam ever break, would flood Zürich, 35 km away, up to the 2nd or 3rd floor - but not to the fifth! Now, that’s smart and forward thinking - and going the extra mile!
My 2 cents
Andy
So that must be N2 or maybe Argon - anything else would make no sence. All noble gasses, even Argon, would be very expensive. I suppose it is N2.
However, any inert gas is “harmful” to humans - not toxic but choking. Water under high pressure sound meaningful to me, as there is an additional cooling effect. I know high pressure water canons for fire extinguishers. These systems are highly efficient with a minimum use of water due to the cooling effect, but is this really considered as "non-destructive to servers?
We use IG55 (50 argon 50 N2) and yes it is really expensive. When you want to shortcut the cost, security is a good target 
What’s known as “Edelgas” in German is not “noble” in english, but known as “inert” gases.
The meaning is the same, they will hardly ever make a chemical (Top electron layer) connection to another element…
Today, “noble gases” is also correct in english, I stand corrected!
My 2 cents
Andy
Really hard to blame anyone but the customers for that.
May I partially disagree? I would “bear” a bit the provider too.
Allowing on-site backup as option is way to receive a bit more money from who don’t want to pay the offsite backup. On the other side, having this option say to the users “better this than nothing” about this kind of… safety measure.
Today we have case that proves “onsite backup” mean “not that much”
When it comes to backups, one is none. Sure you’d expect something at a data center to be more secure than a spare HDD on your desk, but…
But sometimes (as OVH explained) a Datacenter has less security than expected.
http://travaux.ovh.net/vms/index_sbg1.html
http://travaux.ovh.net/vms/index_sbg2.html
http://travaux.ovh.net/vms/index_sbg3.html
http://travaux.ovh.net/vms/index_sbg4.html
it is not a joke, we are looking our first nuclear accident of the cloud computing 
Someone calls that experience and case history.
And in this day and age of DCs, I still find it assuming and somewhat stupid that a company like OVH have the 4 buildings so close together instead of several kilometres/miles apart.
If the buildings had a greater distance between each other, the damage would have been more contained and not so severe.
Again. Experience and case history: bigger spaces, bigger prices for renting or buying.
Also, using container instead of concrete is way cheaper for setup and upgrade, but it has its downsides on building performances.
Did you forget the magical trio “fast, cheap, good”? Same soup, different plate.
Working today in a datacenter, the datacenter mirror is in another building 2km away, the servers are protected against plane crash, fire, water, storm, human, you are recorded all the time, no cell with you or numeric things to steal data.
Obviously it is datacenter for a french bank. Security is a hole in the sea where you drop your money
For whom might concern…
LMG/Linus Tech Tips this evening (CET) released a sponsored video (by Shadow Cloud computing) telling some tales about how wonderful the servers and one location of OVH is.
Fairy tale, in my personal opinion. And i tried to be like some log: help remember.
never trust cloud, backup and system administrator
Sure you can trust the cloud, backups and system administrator @stephdl !
You trust them, but also verify that you can properly recover properly in a reasonable timeframe if anyone of them or any combination of them fails…
We can all guess what OVH did not do due diligence on…