Subtitles of the Movie

When the power goes out, the only thing standing between us and a Server crashing is our UPS. And in a large organization, the UPS might consist of a huge battery room connected to a diesel generator or even a natural gas generator. But in most companies, it's simply a box that has batteries in it and some conditioning equipment. So what happens is, the power comes out of the electrical outlet, and this AC power is used to charge some batteries which are inside the UPS. And these batteries are charged up with the current. That current is then converted to an AC current with the number of watts that are needed to supply power to the Server and all the components that are contained in it, and probably a monitor so we can tell what is going on. And these are then connected to the UPS. So in essence, the components are always running off of the batteries, and the batteries are being recharged by the current coming from the power company. So when the power goes out, the batteries will continue to supply power to the Server and to the monitor, but they can only do it for a certain period of time. That certain period of time will be determined by the number of amps that the UPS is able to supply. So the watts will determine whether it can supply the power at all, and the amps will determine how long it can supply the power. We need to supply power for the Server and the monitor for enough time so that we can do a graceful shutdown or a normal shutdown, so that nothing has to crash and we can shut things down in an orderly manner. That's all we really want out of our UPS - if it will do that, then it's done it's job. Now as we upgrade our Server, two things can happen. Number one we can go out of the wattage reading for the current UPS that we have, because we have put additional cards or drives in our system that now are taking more power to run. And therefore, the UPS might not work at all when it is supposed to. So we need to make sure that we don't go outside of our wattage rating, and most of the Smart UPSs will let us know about the pull from the system. The other thing that can happen is that we can go outside of our amperage reading. We may not be outside of our wattage reading, but because of the things that we have added, we may not be able to power the Server and the monitor for long enough to do a graceful shutdown. So as we upgrade, we need to keep in mind that we might also need to upgrade our UPS. And the vendor can give us some recommendations as to a particular UPS that is made to run a certain range of Server and monitor - but that is what we need to keep in mind. We would never attach printers and especially laser printers to a UPS, because they pull a tremendous amount of power, and in an emergency situation we don't need them anyway. If the power goes out from the power company, we are not concerned with continuing to run as if nothing has gone wrong. All we are concerned with is getting things shutdown in an orderly manner so that nothing crashes. So when we upgrade, we need to also keep in mind that other components will be affected by that upgrade, and the UPS could be one of the components that is affected. In fact that kind of proactive thinking is exactly what most companies look for in a Network Administrator. That is what separates the Network Administrators from the really good Network Administrators. And in our next chapter, we will discuss proactive maintenance of a network - that's next.