title: VirtualBox 101

Running Rocky (or likely RHEL) in a VirtualBox, you'll want to install the guest additions. This requires the Linux headers
which are not installed by default. So we need to
```
dnf install kernel-devel kernel-headers
```
but this is not enough it seems.

See [superuser](https://superuser.com/questions/1532590/guest-additionals-kernel-headers-not-found-for-target-kernel)
and [debugpoint](https://www.debugpoint.com/virtualbox-kernel-headers-not-found-error/)

It seems you have to reboot after installing as above. Nope. Still complains of missing Linux headers.

It seems that dnf is not installing the correct version of Linux headers.

Ok, update the kernel to match the installed headers and reboot.
```
dnf update kernel
```