Networks Europe Sept-Oct 2015 | Page 27

raceway is an important part of the overall cable management system and is usually configured in a grid format – coloured blue and red – providing two separate paths to each cabinet to achieve diverse route, or to house two parallel fibre optic and copper cabling systems. Although it might not be an obvious issue, one of the big mysteries of the data centre world is why cabinets continue to be specified in black. While it is true that black can hide scratches, scrapes, minor dents, and even dirt and dust, a white polyester epoxy powder coat finish increases visibility, reflects up to 80 per cent of the light and, as a result, can help to save around 30 per cent on the total lighting in a typical data centre. A white cabinet is also easier for installers to work in and the fact that it does show up imperfections should act as an early warning system for potential problems down the line. Size Matters As a rule of thumb, it is always better to over-specify than under-specify, as any extra space will almost certainly be utilised by the next generation of server technology. However, some data centre designers are taking this attitude to the extreme by requesting cabinets that can accommodate weights over one and a half tons. This is, ridiculous unless the cabinet is for a UPS or battery rack. Finding enough equipment that weighs this much to test such a cabinet is difficult. To put this into perspective, the massive Huawei CE12816 core data centre switch only weighs 290kg, the biggest Cisco, fully stacked just under 450kg. Then there’s the issue of where to site over a ton’s worth of equipment – how will the building and floor support that level of weight, especially in a multifloor environment? With ever-higher active equipment densities, perhaps the most important role that a cabinet performs is to mount kit in a way that allows it to be cooled efficiently. A cabinet plays a vital role in maintaining the integrity of a cooling system and by controlling the air temperature, server components at the board level are kept within a manufacturer’s specified temperature www.netcommseurope.com and/or humidity range. It’s an issue that’s not going away any time soon. Research from DCD Intelligence, a division of Datacenter Dynamics, found that the number of high-density cabinets and servers – those over 10kW per cabinet – as a proportion of total cabinets rose to 25.2 per cent in 2014. That is quite substantial, but includes the IT service provision sector and an increasing number of end users deploying cloud or virtualisation within their own systems. This means that a handful of hyper-powered