Linux Mint and KVM

I had tried KVM before but stopped at the point of creating virtual machines as I found the management tool is either too manual (command prompt based) or too confusing (GUI with a confusing layout/workflow).  However, this was the experience then.

Yesterday, I came across this article (http://community.linuxmint.com/tutorial/view/1555), and it seems things have moved forward quite a bit since my last attempt.  I thought why not give KVM another try.

The installation is easy with commands below:

Virtualization with virt-manager:
# apt-get install qemu-system
# apt-get install qemu-utils
# apt-get install libvirt-bin
# apt-get install virt-manager

Installing SPICE for KVM remote and local access to VMs
# apt-get install python-spice-client-gtk
# apt-get install virt-viewer

Any users that want to manage VMs will need to be added to the "libvirtd" group.

After the installation, restart the machine.  You can either run the virt-manager from the command line or from the "Start menu".  The interface is much improved (as I recalled) and much more logical.

Once you have setup your virtual hardware using using the virt-manager, the rest is straight forward.

Xubuntu, KVM and Display Resolution

If you are like me who use a KVM switch to control multiple computers, you may run into resolution problem with Ubuntu.

Since the computer is not being connected to the monitor directly, it may not get the DDC information from the monitor to set the resolution correctly.  In my case, I was stuck at 1024x768@60KHz.

A quick google search brought me to this nice post that helps me get pass the 1024x768.

https://www.tecmint.com/set-display-screen-resolution-in-ubuntu/

Here are few quick notes on steps I took.

1) Use cvt   1920   1080 to produce a modeline, e.g.

# 1920x1080 59.96 Hz (CVT 2.07M9) hsync: 67.16 kHz; pclk: 173.00 MHz
Modeline "1920x1080_60.00"  173.00  1920 2048 2248 2576  1080 1083 1088 1120 -hsync +vsync

2) Then made this available for selection

xrandr --newmode "1920x1080_60.00"  173.00  1920 2048 2248 2576  1080 1083 1088 1120 -hsync +vsync

 Use xrandr to get the ID for your display, e.g. VGA-1

$ xrandr

 
 

$ xrandr --addmode VGA-1 "1920x1080_60.00"

3) Test the new resolution option by using your system Display setting tool, e.g.

If the setting works for you, then you can make this permanent by adding a little profile file to /etc/profile.d/, e.g.

$ sudo vim /etc/profile.d/external_monitor_resol.sh

Within this file, just add the two xrandr lines you were using earlier, e.g.

xrandr --newmode "1920x1080_60.00"  173.00  1920 2048 2248 2576  1080 1083 1088 1120 -hsync +vsync
xrandr --addmode VGA-1 "1920x1080_60.00"

Now restart your system.  The new resolution should stay if things are done correctly.

 

Edited 2021-04-22:

It seems there is a simpler alternative.

1) Use xrandr to find out the supported resolutions, e.g.

 

2) In my case, 1920x1080@60 is the resolution I am aiming for.  Now, edit the grub file to tell the kernel about this resolution by adding video=1920x1080@60 as a parameter to the GRUB_CMDLINE_LINUX_DEFAULT option like below:

3) Run update-grub to apply the settings

After reboot, this new resolution should now be available to the system.

 

ref: https://askubuntu.com/questions/973499/wayland-how-to-set-a-custom-resolution