A lot of equipment is installed in server racks besides servers. These server devices serve different purposes such as cable management and energy supply. In this post, we will discover these devices and learn more about them and why are they used.
In short, PDU which stands for power distribution unit is an expensive power strip on steroid. So, it can be defined as a special type of power strips that distributes electricity to server and other devices. Moreover, they are designed to be efficient, safe and able to distribute sufficient energy to all server racks. PDUs excel when multiple three-phase power sources are used together to power server rack equipment.
UPS which stands for Uninterrupted Power Supply is a device that either placed in a server rack or in a separate location and it is serves two purposes. First, it contains a battery pack that feeds server room equipment during a power outage for a finite time and prevents any data corruption due to power outage. Second, Uninterrupted Power Supplies cleans the electricity that feeds the devices. As a result, devices will work better and prevent power related faults. Modern smart UPSs are capable to notify system administrators about power outages and shut down devics safely when the batter is out to run out of charge.
KVM (Keyboard, video, Mouse) switch or known as KVM for short is a device that is used to allow a single mouse, keyboard and monitor screen to be used by multiple computers. Thus, less peripheral device in the server room, especially that most device are rarely accessed directly.
KVM can connect to devices in two different methods. First method is by using a USB and a video cables (VGA, HDMI or DVI) between each device and the KVM. The second method that is usually used by the higher end KVM switches is by depending on IP protocols to connect between the KVM and the devices i.e. using the current network infrastructure to connect remote machines to the KVM switch.
One of the main concepts in network cable management is decoupling. Decoupling means in this case is separating between access switches and end device, by adding a patch device in between. Adding a patch panel helps network and system administrators to reassign network cables between different network devices easily.
Patch panels consist of two sides. First, the rear side which is used to connect between the end machines and the patch panel. Second, the front side which is used to connect between patch panels are network devices.
In real life, server racks have more equipment than mentioned here such as NAS, Tape drives and even GPS-based NTP servers. However, these devices the most important and about no proper server rack is without them.