Yesterday there was a major power outage in Noord-Holland, The Netherlands. This showed us how much we depend on power and how limited we are when there is no power at all. Especially for servers power outages are undesirable since it can cause data loss and service interruptions. In this blog I will explain what actions Yourwebhoster.eu has taken against this.
The servers of Yourwebhoster.eu are stored in room 3 of the Serverius data center in Dronten. The data center is connected to a 10 kv (kilo volts, 10.000 volt) power ring. The main benefit of the ring is that it’s possible to get power from two sides. When a cable breaks or has problems on one side it is possible to switch to the other side of the ring. But it is not as easy as it sounds: Liander (the company who maintains the ring) has to pin point where the problem occurs and disable that part of the ring so they can perform maintenance on it. In the end there always is a power dip from several minutes to several hours or more in the worst case.
Our servers are connected to two UPSes (Uninterruptible Power Supply, a bunch of batteries in short) which takes the role of power supplier on them when the power ring is down. The pro of this is that it can continue supplying power without interruption. This solution is similar of what some Dutch mobile telecom providers have: batteries for their antenna’s. Since the power outage yesterday was +/- 1.5 hours they ran out of juice. So batteries are not the final solution to overcome power outages. It is also a drawback that batteries are not environment friendly and that they require replacement after some time.
In the data center we do not only rely on the batteries: there also are onsite diesel generators who can power the data center. They can generate power as long as there is enough fuel to power them. Special agreements with suppliers for diesel gives us enough fuel to continue generating the generators. But the drawback of diesel generators is that they require several minutes to start up before they can deliver power. That is why we still need the batteries. In an event of a power outage the batteries take over the power supply first. In the mean time the generators are started automatically and when they are powered up they start providing the power to the data center.
The power outage yesterday showed that not every emergency power supply plan did work properly. For example in one data center the diesel generator failed to supply power and all servers went offline. Yourwebhoster.eu has taken actions against this by having two separate power feeds with each their own set of batteries and diesel generator. In the case of an emergency and one diesel generator fails we still have an other generator to continue our services. This is one of the premium features that comes with Yourwebhoster.eu.
The data center was not affected by the major power outage yesterday: Dronten was one of the power grids that was still online. Still this blog is relevant as it explains how we have taken actions against this such events.