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Laptop with small screen + Hyper-V + Install CentOS

So I've got a nice new Lenovo ThinkPad laptop for work. Its got lots of memory and disk, awesome battery life, and it's nice and portable; just the thing for a systems engineer -- it even has a wired ethernet connection (I was previously using a Mac Air). It doesn't have a very large resolution though, just 1366 x 768.

Normally I would use VirtualBox, but on this laptop I'm trying out Hyper-V (because that's what Docker for Windows requires on Windows 10).

I went to install CentOS 7 (7.4), but the resolution of the default framebuffer is larger than can fit on my host's screen. This biggest annoyance about this is that Hyper-V wasn't showing me scroll-bars, and it also only allows to zoom in (for Hi-DPI screens), and not to zoom out. Being able to zoom out was very useful feature in VirtualBox, but the biggest problem was that it cut off the bottom of the screen, so I couldn't proceed with the install. Even text-mode installation was impractical because that's generally the region of the screen you care most about.

Normally, I would use something like 'resolution=800x600' (or a similar video= or vga= arguments....), but it wasn't making a difference; even in 'text' mode installer.

The thing to realise is that the Linux Integration Suite (LIS), which is bundled with CentOS / Linux kernel, has a different display driver. Coming from VirtualBox, I found it rather odd that you can't do things like set VRAM settings or virtual display hardware in Hyper-V, and I rather suspect that this is a major difference between Hyper-V and other hypervisors such as VirtualBox or VMWare ESXi, or VMWare Workstation. This perhaps explains why the resolution/video/vga arguments were not making a difference.

I found this very helpful page on www.netometer.com, which showed me the light. You just need to add a little extra to the video argument.

video=hyperv_fb:1024x768



Do this when you are about to boot into the installer. Unlike the netometer blog post, you don't need to do this using grubby if you do it at install-time; the setting will get carried through.

Great! So now I have a working installation environment. I wonder what other issues will crop up along the way...

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