Ubuntu Server on Virtualbox

Thursday, December 27, 2007

I tried running Ubuntu Server on VirtualBox today and it wouldn’t boot: it just said that the “CPU is too old for this kernel.” Well, I know I have a modern CPU and a modern piece of virtualization software. In addition, the installer ran fine, so what could have gone wrong?

I did some research. Apparently, Ubuntu Server uses a special kernel that requires a CPU with PAE (Physical Address Extension), but the VirtualBox CPU doesn’t support PAE. Uh-oh. So I got out my installation CD again, booted into a recovery console shell, and replaced the kernel:

apt-get update
apt-get install linux-generic
apt-get remove linux-server

After rebooting into the new kernel, the system operated normally.

Sept 7, 2008: As indicated by koomba7, VirtualBox now has a PAE option that can be enabled.


  1. the_punisher says:

    apt-get update i uderstand.

    what is this apt-get install linux-generic supposed to do?

    also the command apt-get remove linux-server is supposed to remove the linux installation right?

    also u said u installed the server on vbox? so does the command even apply to vbox installations, can i similarly write apt-get remove windows that i installed on vbox?

  2. inportb says:

    apt-get install linux-generic just installs the generic linux kernel.
    apt-get remove linux-server just removes the server kernel, which is a special version optimized for servers.

    Since Windows is not managed by the APT system, you cannot apt-get remove Windows ;]

  3. inportb says:

    win-get? that sounds delicious…

  4. antimatter15 says:

    too bad it’s crap. None of the URLs are actually in the repository, just links to other sites. Most of the files in there are old versions, and half of them don’t even work. It still has to deploy the installer windows, that take forever, and require you to answer random questions……

  5. inportb says:

    Yeah, I’d imagine… What about the silent installer option?
    It’s a good idea though.

  6. koomba says:

    or you can just enable the checkbox in the virtualbox settings that says enable PEA and your allll gravy