Unable to set multiple grub terminals using /etc/default/grub

Bug #490451 reported by Sam Creasey on 2009-11-30
This bug affects 13 people
Affects Status Importance Assigned to Milestone
grub2 (Debian)
Fix Released
grub2 (Ubuntu)

Bug Description

Binary package hint: grub2

Using the old /boot/grub/menu.lst setup, if one wanted grub terminals on multiple output devices, a line such as:

"terminal serial console"

would work for putting the grub terminal on both the serial port and the VGA console.

However, in the new /etc/default/grub world, attempting the analog of:
GRUB_TERMINAL="serial console"

produces the error:

Invalid output terminal "serial console"

I suspect this is due to the checking of the GRUB_TERMINAL variable on line 161 of /usr/sbin/grub-mkconfig, where only specific strings are allowed.

Felix Zielcke (fzielcke) wrote :

Currently it's not possible at all to use 2 terminals at once, even by manual hacking of grub.cfg.

Changed in grub2 (Debian):
status: Unknown → Confirmed
Joel Ebel (jbebel) on 2010-03-02
tags: added: glucid
Changed in grub2 (Debian):
status: Confirmed → Fix Released
seph (seph) wrote :

This seems like a pretty serious regression to me. And it's been fixed in both debian and the upstream grub. It's frustrating to find it languishing here in the LTS server release.


Colin Watson (cjwatson) wrote :

We'll fix this in maverick. I'm not certain that I can make an argument that it fits into our stable update policy, although at least the GRUB core is (I think) ready for multiple terminals and it's just a matter of configuration. The upstream patch is here:


Subscribing ubuntu-sru to see what folks there think.

Colin Watson (cjwatson) wrote :

grub2 (1.98+20100527-1) unstable; urgency=low

  * New Bazaar snapshot.
    - Support multiple terminals in grub-mkconfig, e.g.
      GRUB_TERMINAL='serial console' (closes: #506707).

 -- Colin Watson <email address hidden> Tue, 01 Jun 2010 11:24:38 +0100

(Merged into Maverick as 1.98+20100614-1ubuntu1 and later.)

Changed in grub2 (Ubuntu):
status: New → Fix Released

> We'll fix this in maverick. I'm not certain that I can make an argument that it fits into our stable update policy,

Fixing a regression in an LTS release with regard to prior-to-LTS releases most certainly should be in your stable update policy. It's unacceptable to upgrade to a release which is intended to be stable and installed for 2 years only to have to live with regressions for that long.

I most certainly understand not allowing new features into an LTS but any identified and fixed regression should most certainly be backported. IMHO. :-)

stchesmeli (stchesmeli-ext) wrote :

I'm agree with Brian.
We use LTS here in production (more than 3000 servers) because of Long Term Support. We can't upgrade to a non LTS.
It's unbelievable that fixed regression isn't backported on a LTS!

Piotr (pm-plusnet) wrote :

I've already spent few hours trying to setup grub2 to support both serial and console on 10.04.1 LTS. No success till now, perhaps because of above decisions.

Is there any way to enable both serial and console in grub2 or I should rather look at lilo (I have used it for many years, but would prefer to stick with the now default bootloader for ubuntu)?

And +1 for Brian proposition.

undefined (undefined) wrote :

i took the patch collin referenced, applied it to the installed files (ie /etc/grub.d/00_header & /usr/sbin/grub-mkconfig) as a proof of concept, fixed some bugs (bashisms & unquoted variables in comparisons), and once i proved the changes worked, i applied them to the grub2 source package, resulting in the attached patch.

1. apt-get source grub2
2. apt-get build-dep grub2
3. apply patch
4. dpkg-buildpackage -D -us -uc

the patch will only apply to 1.98-1ubuntu10 because it adds an entry to the debian changelog.

i will also attach the patches to /etc/grub.d/00_header (grub script fragment) & /usr/sbin/grub-mkconfig (sh script) in case somebody doesn't want to go through the hassle (though the more proper fix) of building the source package and just wants to patch the already installed files.

 * built in an up-to-date (including lucid-proposed) lucid amd64 pbuilder chroot on a debian lenny amd64 installation
 * binary package only tested on a single lucid amd64 installation with GRUB_TERMINAL="console serial"

S. D. (akjag) wrote :

Care to post the backported deb in a PPA?

That would be quite nice indeed...

Richard Laager (rlaager) wrote :

This is somewhat working in Natty, but only one terminal (whichever is specified first) accepts input. Some Google searching suggests I want "terminal --timeout=5 console serial" but that doesn't work either.

Richard Laager (rlaager) wrote :

This definitely works for me in Precise.

Rolf Leggewie (r0lf) wrote :

lucid has seen the end of its life and is no longer receiving any updates. Marking the lucid task for this ticket as "Won't Fix".

Changed in grub2 (Ubuntu Lucid):
status: New → Won't Fix
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