Remote Linux / UNIX / Windows Server Management With KVM over IP

last updated in Categories Linux, Networking, Sys admin, Troubleshooting, UNIX

KVM (Keyboard, Video, Mouse) is a switch or hardware device allows a single keyboard, video monitor and mouse to control more than one server one at a time. KVM can be local device or remote device working over IP network. KVM devices extensively used in server farms where it is only necessary to periodically access box. KVM allows you to access your server even if a remote public network connectivity is down.

KVM Usage

  • Troubleshoot problems
  • Install Linux / *BSD remotely
  • Access BIOS and change settings remotely
  • Access the server even if network is down
  • Access the server even if it is very busy or has stopped responding to network connections.
  • Reset root password
  • Run fsck and lots of other stuff

KVM over IP

KVM over IP devices are typically connected to a system’s standby power plane so that you can see entire boot process or access BIOS. They work over TCP/IP. You can access your server using a web browser or standalone client application provided by vendor.

With this technology you can control entire server rack from the office, or around the world. Most KVM switch integrates KVM and serial devices into a single management console for all your servers, network devices and infrastructure.

Today you don’t have to put external KVM devices hanging off the back of the server rack. You need to just insert add-on card (daughtercards) to enable KVM support.

Typical implementation

| Server Rack  |
| Server 1      | ===>  VPN Router
| Server 2      |
| Server 3      | --->  Public Router
| Server N      |
| KVM Switch  |

To manage server you need to connect server via VPN client. Once logged in you can access each server using KVM even if public network is down. Public router allows rest of the world access your web or mail server but not KVM device.

KVM in Action

First, connect to your backend network using VPN client.
Once connected open KVM application supplied by your vendor. Following is application supplied by Supermicro vendor

(Fig. 01: Login Screen – Click to enlarge image)

(Fig. 02: Connected to my KVM device – Click to enlarge image)

(Fig. 03: Server sensor data – Click to enlarge image)

Access Server Using KVM  Console
(Fig. 03: Accessing RHEL server using remote console – Click to enlarge image)

Server PowerStatus
(Fig. 05: Control Server Power Remotely – Click to enlarge image)

Further Readings:

I hope this small post gives out introductory information about KVM over IP. For further information please consult following resources. I think KVM will be standard feature on the motherboard in coming days. Tomorrow, I will write about “Intelligent Platform Management Interface” (IPMI) technology developed by Intel and others.

Posted by: Vivek Gite

The author is the creator of nixCraft and a seasoned sysadmin, DevOps engineer, and a trainer for the Linux operating system/Unix shell scripting. Get the latest tutorials on SysAdmin, Linux/Unix and open source topics via RSS/XML feed or weekly email newsletter.

1 comment

  1. Great article! I just tried the KVM over IP performance from Minicom ( – will soon test Raritan before I decide on my next switch…

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