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tech_notes:pikvm [2025-08-10 Sun wk32 09:43] – [PiKVM] baumkptech_notes:pikvm [2025-08-10 Sun wk32 20:30] (current) – [Terminal versus Graphical] baumkp
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 {{tag>linux kvm ipmi pikvm bmc}} {{tag>linux kvm ipmi pikvm bmc}}
 ======PiKVM====== ======PiKVM======
-I purchased a PiKVM kit in 2021, and got it operational at that time.  I did not need to use it until recently, 2024-09. Basically a special 'hat' is mounted on a standard Raspberry Pi 4, the smallest memory unit type being sufficient (2 GB).  The kit was complete with all the required parts, such as the hat, Raspberry PI, a case, small OLED display and various cables.+I purchased a PiKVM kit in 2021, and got it operational at that time.  I did not need to use it until recently, 2024-09. Basically a special 'hat' is mounted on a standard Raspberry Pi 4, the smallest memory unit type being sufficient (2 GB).  The kit was complete with all the required parts, such as the hat, Raspberry PI, a case, small OLED display and various cables.  The PiKVM is V3 HAT with RPi V4 2GB.
  
-After about 3 years of being shelved the OS would not update.  It was easier to simply re-image with the latest version of the software. I followed the [[https://docs.pikvm.org/flashing_os/#download-the-image|Flashing PiKVM OS image]] instructions, using the Linux CLI image flash option. I tried again after about a year and the update was large, took a long time and failed the first try.  I suggest that updating need to be completed more frequently than yearly, perhaps every 1 - 3 months.+After about 3 years of being shelved the OS would not update.  It was easier to simply re-image with the latest version of the software. I followed the [[https://docs.pikvm.org/flashing_os/#download-the-image|Flashing PiKVM OS image]] instructions, using the Linux CLI image flash option. I tried again after about a year and the update was large, took a long time and failed the first try.  I suggest that updating needs to be completed more frequently than yearly, perhaps every 1 - 3 months.
  
-The PiKVM builtin display shows the KVM IP address, but I just used Linux commands to find from my LAN, e.g. ''sudo nmap -sn 192.168.1.1/24''.  Once I go satisfactorily operation I followed the instructions to change the passwords on the PiKVM and placed the related information into my password manager.+The PiKVM builtin display shows the KVM IP address, but I just used Linux commands to find from my LAN, e.g. ''sudo nmap -sn 192.168.1.1/24''.  Once I got satisfactorily operation I followed the instructions to change the passwords on the PiKVM and placed the related information into my password manager.
  
-My router computers built in BMC/IMPI had failed and was difficult to use, particularly any time it was reset.  Hence I disabled the BMC VGA system and used the main CPU builtin GPU to the PiKVM with a USB C to USB A cable for the keyboard and mouse access.  I used a jumper on the motherboard to disable the BMC VGA to ensure it would not interfere with operation.  Basically I was no longer using the built in KVM.+My new router/server computer as of 2024/12 does not have build in BMC/IMPI, so the PiKVM is handy for this application.  When I do not need I can turn of the power. ++old tl;dr;|My router computer's built in BMC/IMPI had failed and was difficult to use, particularly any time it was reset.  Hence I disabled the BMC VGA system and used the main CPU builtin GPU to the PiKVM with a USB C to USB A cable for the keyboard and mouse access.  I used a jumper on the motherboard to disable the BMC VGA to ensure it would not interfere with operation.  Basically I was no longer using the built in KVM.++
  
 ====Browser Video mode options==== ====Browser Video mode options====
-In Firefox make sure that [[https://www.openh264.org/|OpenH264]] is installed and activated to use the default WebRTC H.264 option in PiKVM.  Otherwise try Legacy MJPEG if this does not function for whatever reason.+In Firefox make sure that [[https://www.openh264.org/|OpenH264]] is installed and activated to use the default WebRTC H.264 option in PiKVM.  Otherwise try Legacy MJPEG if this does not function for whatever reason.   See PiKVM Handbook [[https://docs.pikvm.org/video/|Video modes]] for more information on these options. 
 + 
 +PiKVM V3 supports maximum resolution 1920x1080@50Hz, 60Hz will not work. You can use any other resolution less than the specified one, for example: 1600x1200@60Hz, 1280x720@60Hz, etc. If you have problems with the video, follow [[https://docs.pikvm.org/edid/|this guide]].  The PiKVM V3 standard default resolution is 1280x720@60Hz, as a basic terminal KVM this is adequate.  
 + 
 +====Terminal versus Graphical==== 
 +The final output mode of the computer the PiKVM is attached to is determined by the attached computer.  Normally servers boot into terminal mode (CLI = command line interface) and desktops boot into graphical mode.  I often load a graphical mode on to my servers to allow VNC access, however I usually leave the default boot mode to terminal as my servers are headless.   As the primary purpose of a KVM is full remote access during boot, a graphical user interface is not really necessary.  
 + 
 +If graphical mode is really wanted used ''sudo systemctl isolate graphical.target'' and to switch back to CLI mode ''sudo systemctl isolate multi-user.target''. On the PiKVM V3 I noticed the return to multi-user target does not function, however the shortcut ''Ctrl+Alt+F1'' does work. Note this does not change the default boot mode, which can be done by changing the ''isolate'' directive with ''default'', e.g. ''sudo systemctl default graphical.target''.  The current default directive can be checked with ''systemctl get-default''. 
 + 
 +The PiKVM virtual keyboard can be used to give the following commands: 
 +  *''Ctrl+Alt+F1'' switch to tty 1 (main boot CLI) 
 +  *''Ctrl+Alt+F7'' switch to graphical user interface. 
 +//The ''ctrl'' and ''Alt'' keys can be held on by right clicking on the virtual keyboard.  Also the ''ctrl'' and ''Alt'' keys can be depressed on the main keyboard and then the function key on the virtual keyboard depressed. This ensures the local computer does not capture and action the control key input.// 
 + 
 +A reasonable description of Linux boot targets is given [[https://linux-tips.us/change-between-cli-and-gui-mode/|here]] and [[https://www.cyberciti.biz/faq/switch-boot-target-to-text-gui-in-systemd-linux/|here]] 
 + 
 + 
 ====Update OS==== ====Update OS====
   *PiKVM OS (and the underlying Arch Linux ARM upstream) often receives software updates. After installation, it makes sense to update the OS.   *PiKVM OS (and the underlying Arch Linux ARM upstream) often receives software updates. After installation, it makes sense to update the OS.