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I was running 10.10 64-bit quite happily in VirtualBox 4.0.4 64-bit on Windows-7 Professional 64-bit SP1. This morning I upgraded VBox to the latest 4.0.6; 10.10 still worked just fine. The I did an online upgrade to 11.04 and now the Ubuntu VM will not come up. It just sticks at the Ubuntu screen with a row of dots and that is it.

How can I troubleshoot this so I can get it to boot. I really don't want to have to do a clean install if I can avoid it.


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Much simpler/less time-consuming solution:

I solved the problem by getting into the console mode (Ctrl-Alt-F1) and logging into Ubuntu from that console, then I manually created a mount point for the cdrom and mounted the Guest Additions cdrom, and finally did run the Guest additions script. That solved the problem.

sudo mkdir /media/cdrom sudo mount /dev/cdrom /media/cdrom/ sudo /media/cdrom/

So, it might be advisable to uninstall Guest Additions before the upgrade from 10.10 to 11.04, as the old version might prevent the upgraded system to boot properly into desktop.

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I had to do this as just uninstalling the additions didn't work. – Simon Nov 8 '11 at 2:26
This worked great for me... thanks for the answer! – Clayton Jun 19 '12 at 23:20

First you should try to start Ubuntu in recovery mode or with a previous kernel by selecting from the Grub menu (appears when holding down Shift while booting). We can also run a maintenance shell where we could remove unwanted applications or update Guest Additions to the current version (in case this was not done already).

It may also help booting to disable 3D acceleration in the display properties from Virtual Box Manager.

In case you are still unable to start your virtual machine after an upgrade you may consider to go back to the snapshot before you upgraded or to restore your backup from the virtual machine before having performed the upgrade to 11.04.

In addition to an online upgrade we now have the additional option to upgrade an existing system by using the installation CD-ROM image. After choosing Install Ubuntu you will have the option to upgrade your system by keeping your personal data and system settings:

enter image description here

A similar option will also be available when booting your upgraded Ubuntu 11.04 from the installation CD-ROM image of 11.04. By this you may be able to reinstall or repair your Ubuntu without deleting data and settings in /home.

Before upgrading it is always recommended to backup your virtual machine files, and in addition to backup the content of your /home directory to be able to restore it later.

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Thanks very much for this, most helpful. I didn't have 3D support enabled but by booting into recovery mode I was able to remove the VBox 4.0.4 Guest Additions (built against the 10.10 kernel) and install the VBox 4.0.6 Guest Additions whioch of cousre then built against the 11.04 kernel and this resolved my problem and the VM now boots. I guess that is a lesson for me for the future. When upgrading across major versions, always uninstall the Guest Additions before the upgrade and then re-install afterwards! – ChrisJ May 7 '11 at 8:30
Thank you for this very good point. I was erroneously assuming that Guest Additions were already updated. – Takkat May 7 '11 at 9:20
@ChrisJ how did you uninstall the guest additions? It is most helpful when people explain the steps they did to solve a problem! EDIT: found it, /opt/guest-additions/ – orange80 Jun 20 '11 at 4:09

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