Locked out my user from sudo

[staubsaugen]

I installed kubuntu 10.10 with an encrypted LVM filesystem and I then put on virtualbox and wanted to get the USB passthrough working so I did sudo usermod -G vboxusers <username>. What I didn't realize was that it took away all the other groups. Now I can't sudo anymore. I then wanted to boot into single user mode, but I can't figure out how cause I don't get a grub screen so that I can edit the boot line. I need to add myself back to the admin group somehow. Any ideas would be greatly appreciated!!!

[CharlesA]

Are you able to boot into a root shell from recovery mode?

Not sure if that'll work due to the encrypted LVM.

[staubsaugen]

I don't see any sort of option for a recovery mode anywhere.

[CharlesA]

Reboot and hold shift to get to the grub menu and select recovery mode.

It should be there.

[staubsaugen]

Thank you so much! That was exactly what I needed!

[staubsaugen]

Actually, can you tell me one more thing? What are the groups the default user is in so I can add myself back in?

[CharlesA]

They are just in the admin group as far as I know.