Question: **This question is Not about how to set up VPN on an Ubuntu server.** 

Edited: I think what I'm looking for is the way to set up a PPTP VPN client on my Ubuntu server by command line.

I have an Ubuntu server running and connected to the internet. I also have a VPN service (PPTP) running on another Linux machine. Now all I want to do is configure this Ubuntu server so that all the internet traffic it generates goes through the VPN.

How can I achieve this?

Answer: 
Use:

```
grub-editenv create

```

This will clear grub environment file and should boot clearly the next time.
I could solve that issue by adding the following line to `/etc/default/grub`

```
GRUB_DISABLE_OS_PROBER=true

```

...and then running `sudo update-grub`.

**Explanation:** The file `/boot/grub/grub.cfg` is generated by running `update-grub` using the files in `/etc/grub.d` and `/etc/default/grub`. Therefore you should not edit `grub.cfg`, but it can be helpful to find out why the timeout is set. Search for lines starting with `set timeout=` and then search for the next line starting with `### END /etc/grub.d/ ...`. This might give you hints which script sets the timeout. In my case the os-prober script was responsible for the timeout. It turns out that there is a 10s hardcoded timeout in `/etc/grup.d/30_os-prober` which is not set by `GRUB_TIMEOUT`. You can either disable os-prober by `GRUB_DISABLE_OS_PROBER=true` or edit `/etc/grup.d/30_os-prober` or use `GRUB_OS_PROBER_SKIP_LIST` to skip some of your harddisk partitions (30\_os-prober is used when another OS is found somewhere). See [this Q&A for details](https://askubuntu.com/questions/453038/update-grub-ignoring-some-options-in-etc-default-grub). As others pointed out another reason might be the *recordfail*, in this case set `GRUB_RECORDFAIL_TIMEOUT=$GRUB_TIMEOUT`.