KarmicGrub2
Launchpad Entry: foundations-karmic-grub2
Created: ColinWatson
Contributors:
Packages affected: grub, grub2, grub-installer
Summary
Move to GRUB 2 as the default boot loader.
Release Note
This section should include a paragraph describing the end-user impact of this change. It is meant to be included in the release notes of the first release in which it is implemented. (Not all of these will actually be included in the release notes, at the release manager's discretion; but writing them is a useful exercise.)
It is mandatory.
Rationale
This should cover the _why_: why is this change being proposed, what justifies it, where we see this justified.
User stories
Assumptions
Design
By and large, GRUB 2 appears to be in a reasonably good state now, after a long period when we were unable to seriously contemplate a switch. There are some things to fix, of course, but for the most part these look tractable. The kernel team did extensive testing, which suggests a strong performance.
Implementation
Unsorted BoF dump
* Some minor issues to fix, e.g. tidy up config updates
* LVM:
- currently grub cannot boot from /boot for LVM, needs to use lilo.
- check if grub2 can boot /boot LVM - and hence remove the need for the lilo on ISO
* xfs: grub2 was known to have race condition installing grub - check racy code is now fixed
* grub2 EFI/UEFI
Mac and x86 PC with EFI support needs checking
need to check EFI bootloaders on x86 H/W when we get the hardware
* PPC OpenFirmware?
* Modifying the default boot options (e.g. default OS to boot and timeouts) once booted to change bootup next time around:
legacy grub has grub-reboot and grub-set-default to change boot. Can this be achieved in grub2? grub2 seems to
provide ability to do this but had different commands to do this.
e.g. for reboot - show menu, for failed kernels
grub-reboot
- for single shot mode - do once, go back to default mode thereafter
grub-set-default
- e.g. for last good boot
* Boot key
user holds key - e.g. press shift shows menu, otherwise just continue boot process
Make sure we use different key in grub2 from that in usplash:
grub 1 - timeout and escape
grub 2 - shift, alt, control, (should not use alt, Apple Macs)
make sure grub2 uses shift to get into grub2 menu
usplash - use a different key
* Older Hardware:
- grub2 - test on Certification Farm
- xubuntu - ask community to test as they probably have more legacy Hardware
- debian
- get community to test https://wiki.ubuntu.com/KernelTeam/Grub2Testing
Migration
* grub1 -> grub2 upgrade
Go for chainloading grub2 in the upgrade
Grub 2 for new installation
Karmic +1 to drop grub 1?
Make update-grub only update grub2
Do automatic change to grub 2:
- detect chainloaded from grub 1
- then install grub 2
change menu.lst in grub 1 - with zero timeout and chainload grub2
leave stage1.5 (don't scrub it)
- grub loads grub stage 1.5 (in 32K start of partition)
- then loads grub stage 2 from fs
- then chainloads grub2 (2nd stage)
Note: do not remove grub stage1.5 + stage2
- device map (hdX,Y) may not 100% correct on some systems
* purge process of grub1 removes menu.lst - this is an issue that needs fixing.
- dependency issues:
make sure postrm is removed from grub
grub-pc replaces grub
use breaks to stop clobbering of menu.lst on purge
Test/Demo Plan
It's important that we are able to test new features, and demonstrate them to users. Use this section to describe a short plan that anybody can follow that demonstrates the feature is working. This can then be used during testing, and to show off after release. Please add an entry to http://testcases.qa.ubuntu.com/Coverage/NewFeatures for tracking test coverage.
This need not be added or completed until the specification is nearing beta.
Unresolved issues
This should highlight any issues that should be addressed in further specifications, and not problems with the specification itself; since any specification with problems cannot be approved.
See also
Previous (misnamed) specification in this series: FoundationsTeam/Specs/Grub2ByDefault