A KVM Switch is typically required for a Windows-based server. A KVM switch, where the abbreviation stands for Keyboard Video Mouse, makes it possible to control several computers with a mouse, keyboard and display. The user can choose at any time the computer he wants to control, and switches instantly from one to the other. Some recent KVM switches also allow you to share not only USB devices but also audio (speakers, microphone).
The user connects a monitor, keyboard, and mouse to the KVM device. It then uses cables (or configurations to use over the internet) to connect to the computers the user wants to control. Using the KVM switch buttons allows you to choose the controlled computer from those connected to the switch, as the switch transmits signals between a computer and the keyboard, mouse, and monitor depending on the computer selected. Most KVM switches also allow you to choose the controlled computer using special commands on the keyboard. Some KVM devices also send signals to computers that are not currently selected to ensure that they do not think they are disconnected from the monitor, mouse, and keyboard. KVM switches differ in the number of computers that can be connected to them, ranging from 1 to 64. Enterprise-class KVM devices can also be chained together to allow even more computers to be controlled from a single set of keyboards, monitors, and mice.
Advantages and Disadvantages of KVM Switch
It is economical (a set of peripherals for several computers), but especially ergonomic when the same operator must control several computers since the keyboard, video and mouse remain the same. Compared to purely software-based methods of remote administration, which run as a separate process in the operating system (e.g. VNC, terminal server), a KVM switch has the advantage that it allows remote administration even if the corresponding software component does not run on the remote computer or is defective. For example, the BIOS settings of remote computers can also be changed via a KVM switch.
The disadvantage is that there is no possibility to see the display of several computer screens at the same time. The KVM switch may affect the resolution and frame rate. Complex settings and installation of proprietary software for models that transmit information over the network.
KVM over IP
KVM over IP is particularly important in the professional sector. In a switch with KVM-over-IP technology, the keyboard, monitor and mouse are not connected directly to the KVM switch, but to a networked PC (remote client) with a Java-based browser or special software. This communicates via TCP/IP networks with the KVM over the IP switch to which the computers are connected. The switch converts the screen outputs of the computers (encoders) and transmits them to the remote client (decoder), which sends the keyboard and mouse information to the switch in the opposite direction. KVM over IP allows the control of the connected computers without physical access on the KVM switch, and thus remote control from any workstation in your network or via the Internet.
Software KVM (KVM Console)
Often the web hosts provide an alternate solution to control the dedicated servers – a software-based KVM Console. Usually, this is sufficient for Linux servers since the main two reasons we need a higher level of control are getting blocked to SSH in case of wrong SSH configuration or a buggy security rule and the second reason is getting a way to interact with the bios of the server.