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Hyper-V: How to change screen resolution in CentOS / Red Hat Enterprice Linux virtual machine

I’m thinking of doing a switch to GNU/Linux as my desktop OS yet again! (My last GNU/Linux desktop experience lasted for 5 years, then back to Windows.) This time giving CentOS 7 a try.

Why CentOS? I particularly like that, it’s one of the few GNU/Linux distributions out there providing LTS, which means I will have a stable development machine for at least 2 – 3 more years.

Making a decision to migrate or stay with Windows among other things is testing various aspects of the distribution such as how things works out of the box, installing various development tools / applications required for my area of work, etc..

For testing, CentOS 7 was installed on Hyper-V virtual machine. What I didn’t liked after the installation was the screen resolution that the machine was set to (1152×864) with now way of chaining it either from KDE System Settings or Hyper-V virtual machine properties.

After a bit of digging I learned that there is a frame buffer driver for Hyper-V and that CentOS unlike other distributions I have worked with, provides a tool called grubby for managing grub.cfg. It’s way easy to work with grubby than editing “/etc/default/grub” for example and running update-grub.

To set the desired screen resolution under Hyper-V. Open a terminal, and su. Then execute:

grubby --update-kernel=ALL --args="video=hyperv_fb:1280x1024"

and reboot the system.

NOTE: Replace 1280×1024 with the desired screen resolution.

See grubby man page if you need further info on what the a bought line does.