Ubuntu
ubiquity package

Installing to USB drive (sdb) using automatic partitioning writes MBR to internal drive (sda) without warning or giving option to change

Bug #684292 reported by komputes
18
This bug affects 3 people
Affects Status Importance Assigned to Milestone
Release Notes for Ubuntu
Invalid
Undecided
Unassigned
ubiquity (Ubuntu)
Invalid
High
Colin Watson

Bug Description

Binary package hint: ubiquity

Ubiquity on 10.10 installs MBR on sda regardless of the fact that the full install went on sdb (external USB).

Expected behavior (which was default in previous versions of ubiquity where we had an "Advanced" button at the end) is that if you install to an external drive, the MBR gets placed on the external drive device (example: if sdb is a usb drive and / is being installed on sdb1, then sdb should be the recipient of the grub-install's MBR placement).

This is a type of regression which looks like a previous regression bug I reported (Bug #549756) which was fixed and now has crawled back into Maverick. When installing to an external drive, the idea is that the external drive will be self sufficient to boot itself on any number of machines, meaning it will contain the MBR and the root partition. However when installing to an external device, using the standard simplistic view, there is no mention of the MBR being written to the internal disk.

The result is a USB drive which will not boot and a GRUB menu on your internal drive with extra entries. It may also cause a windows user installing to USB (not wanting to risk his MBR), to lose his MBR on the internal drive to GRUB.

ProblemType: Bug
DistroRelease: Ubuntu 10.10
Package: ubiquity 2.4.8
ProcVersionSignature: Ubuntu 2.6.35-22.33-generic 2.6.35.4
Uname: Linux 2.6.35-22-generic i686
NonfreeKernelModules: wl
Architecture: i386
Date: Thu Dec 2 16:35:04 2010
LiveMediaBuild: Ubuntu 10.10 "Maverick Meerkat" - Release i386 (20101007)
ProcEnviron:
 LANG=en_US.UTF-8
 SHELL=/bin/bash
SourcePackage: ubiquity

See original description
Revision history for this message
komputes (komputes) wrote :
komputes (komputes)
description: updated
komputes (komputes)
tags: added: regression-release
Revision history for this message
Evan (ev) wrote :

Can you reproduce this using a regular live CD setup? You seem to be using a loop mounted ISO here, and I'm wondering if that's playing a role.

Changed in ubiquity (Ubuntu):
importance: Undecided → Critical
status: New → Incomplete
Revision history for this message
komputes (komputes) wrote :

Using a loop mounted ISO is the cause of this issue. However why should that affect a partition that will not be touched?

Changed in ubiquity (Ubuntu):
importance: Critical → Undecided
status: Incomplete → New
Revision history for this message
komputes (komputes) wrote :

I'm sorry, no. I made a mistake using a loop mounted ISO is the cause of Bug #684280.

This was done from a LiveCD to a computer which has an external USB key plugged in. I used the "Simple" partitioning interface to select sdb (external usb disk).

Revision history for this message
komputes (komputes) wrote :

Evan, I have been able to reproduce this issue using a regular 10.10 and 11.04 Beta Live CD. The problem is still present in natty (ubiquity 2.6.9).

The action of installing to a USB disk can only be done from the advanced partitioning screen. If you use the automatic or "smart installer", installing to sdb will install the MBR to sda without giving an option to change. After a reboot the MBR will boot from the internal drive and unless the USB drive is present GRUB will fail. Booting from the USB stick will fail as there is no MBR on that disk. This is a major problem as USB creator is nice but does not offer all the possibilities as a full installation on an external drive.

Brian Murray (brian-murray)
tags: added: ubiquity-2.4.8
komputes (komputes)
tags: added: css-sponsored-p
Colin Watson (cjwatson)
Changed in ubiquity (Ubuntu):
status: New → Triaged
importance: Undecided → High
assignee: nobody → Colin Watson (cjwatson)
Colin Watson (cjwatson)
summary: - Installing to USB drive (sdb), writes MBR to internal drive (sda)
- without warning or giving option to change
+ Installing to USB drive (sdb) using automatic partitioning writes MBR to
+ internal drive (sda) without warning or giving option to change
Revision history for this message
Colin Watson (cjwatson) wrote :

I haven't been able to reproduce this with a current precise daily in my tests in a hacked-up virtual machine: I gave it two disks, /dev/sda and /dev/sdb, installed a stunt version of udevadm that substitutes ID_BUS=usb for any ID_BUS= line, and told the installer to automatically partition the whole of /dev/sdb. It correctly installed the boot loader to /dev/sdb, and the resulting system boots when given only /dev/sdb as a disk.

Colin Watson (cjwatson)
Changed in ubiquity (Ubuntu):
status: Triaged → Incomplete
Pete Graner (pgraner)
Changed in ubuntu-release-notes:
status: New → Invalid
Revision history for this message
dino99 (9d9) wrote :

maverick have reached EOL now

Changed in ubiquity (Ubuntu):
status: Incomplete → Invalid
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