If you upgraded to Ubuntu 9.10, and rebooted, and it hasn't come back up, here's what to do
The first thing you try is the console https://rimuhosting.com/cp/vps/console.jsp . Add your key or setup a password and then ssh into the host it gives you to see if you actually have this problem.
If you can see the console and it says something like this
mountall:/proc: unable to mount: Device or resource busy
mountall:/proc/self/mountinfo: No such file or directory
mountall: root filesystem isn't mounted
init: mountall main process (736) terminated with status 1
General error mounting filesystems.
A maintenance shell will now be started.
CONTROL-D will terminate this shell and re-try.
Give root password for maintenance
(or type Control-D to continue):
Then this is the current bug, and the good thing is, its a very easy fix involving just the kernel upgrade.
In the user CP, click on your VPS so you get to a page looking like this
Look for where it shows your kernel and a 'Change' button. Click the Change button which brings you to a page like this.
Now select the latest kernel, then click the "Change Kernel" button. In this screenshot the latest kernel is 188.8.131.52-xenU.i386.
This will reboot your VPS with the latest kernel.
That's it, done. If you continue to have problems, then just drop us an email at support, we're only too happy to help
Update: We had one customer whom seemed to continue having problems, the fix was to just to disable /dev/pts and /sys mounts in /etc/fstab.