Visit to Swisscom Computer
Centre, Bern, 29th March 2000
Who: Tony, Anne & Dave with Jean-Claude Brahier. Main contact there was Werner Pfaeffli.
The raised floor area is split across 3 floors which were built underground (due to concerns about terrorists). Machine room areas have height of around 3.5m below false ceiling/air conditioning ducts.
Service continuity and data security are ensured through use of a remote site. The separation (1km) is simply because they had the building, but 1km is felt to be enough to protext against most problems.
Total electrical consumption is 800kW. They have a UPS and diesel generators to protect against electrical supply failures (these occur 1-2 times per year).
Their machine room looks tidier than ours, although some old equipment was lying in one area waiting for removal. They have problems with obsolete cables being left in the false floor void, but their void is cleaner than ours.
False floor depth of 45cm is seen as tight; would prefer at least 60cm.
They have regular contacts with Crédit Suisse in Zurich to discuss machine room issues.
They have a Cerberus AlgoRex fire/smoke detection system which has programmable sensitivity. They do not have any “High Sensitivity Smoke Detectors” (presumably VESDA systems by another name) as these are “too sensitive” (can be set off by paper dust?) and the Fire Brigade won’t accept that these detectors create alarms directly.
They do not have automatic extinction.
They do not use racks to enclose equipment to limit smoke spread/damage, but might consider moving to an arrangement with a set of smaller, isolated, rooms.
Power cables used be run directly from the distribution board to equipment, but this system has now been replaced by their equivalent of “normabars”.
The distribution board is open to operators as plastic covers protect access to the conductors. This means operators can isolate/reset breakers as necessary.
They have an emergency power off only in the machine room areas. These are apparently not tested on any regular basis.
Their UPS provides 50minutes autonomy which is ample as diesel generators can start up in around 5 minutes.
Pfaeffli comments that a UPS should be run at 50-70% of the rated capacity. Theirs runs at only 20-30% of capacity. Not entirely clear if this is because they have a redundant system (i.e. one half can cope with load if other half fails) or if it is because post-mainframe loads are lower. Certainly there was a nice schematic on one wall which showed a fully redundant electrical supply system, but not all elements were installed (e.g. only 2 diesel generators, not 4).
UPS and diesels are tested monthly. Once or twice each year they will run on a Sunday using the diesels instead of the public supply. Diesel tanks have 90,000l capacity—1 week’s autonomy.
UPS battery lifetime is 12-15 years.
Cold air is injected into the false floor and extracted from the false ceiling. Floor tiles with vents are used to vary flow according to need. Air conditioning units are powered via the UPS as otherwise temperature rises too quickly in event of power failure.