GRUB2 many questions

[martyfelker]

Just isntalled Fedora 16 and it looks good. I did however have to install the bootloader to the MBR. Either I will need to be able run "update-grub" and add Ubuntu, openSUSE and Windows 7 to the GRUB menu or find a way to to install grub to /dev/sdb2 - a primary partition. / is mounted on a LVM Volume. I just looked around and even if I were to hand edit /etc/default/grub what do I do to change the menu? Many questions about GRUB2. Can anybody point me to the latest Fedora docs? Could I copy /etc/default/grub from Ubuntu or openSUSE? If I copy the "update-grub" command will it work? The /etc/grub.d/30_Os-prober file exists.

[smr54]

Heh, that's one problem we've been discussing on the testing list---update-grub is an Ubuntu command. You will need to run

grub2-mkconfig -o /boot/grub/grub.cfg

I have a little page, a work in progress really, so that I won't have to look it up each time.

http://home.roadrunner.com/~computertaijutsu/grub2.html


It's very incomplete at present, only covers adding other distros to the menu, and making changes to things like the timeout and the rhgb quiet.

See if it helps though, it should aid you in adding the other systems.

[martyfelker]

As far as I can I can determine the correct command should be grub2-mkconfig -o /boot/grub2/grub.cfg. I have successfully update that file and the custom.cfg so I can verify at the moment but somebody asked me the correct correct to correct.

[tox]

As far as I can I can determine the correct command should be grub2-mkconfig -o /boot/grub2/grub.cfg. I have successfully update that file and the custom.cfg so I can verify at the moment but somebody asked me the correct correct to correct.

i believe that is the correct command, as shown in one of my Links ( the archlinux one i think )

---------- Post added at 10:09 AM ---------- Previous post was at 10:07 AM ----------

i think there is a command called update-grub2 though that maybe a DEbian command i dunno if its a all Distro grub2 command

[stoat]

i think there is a command called update-grub2 though that maybe a DEbian command i dunno if its a all Distro grub2 command

Fedora used to have the update-grub2 command. I played with Fedora's grub2 in Fedora 12 and 13. Fedora 12 had the update-grub2 command. In Fedora 13, it was gone and I used grub2-mkconfig. There was a README somewhere amongst the grub2 stuff that listed the commands and other interesting stuff about Fedora's grub2. The Fedora 13 README did not mention anything about update-grub2. Maybe Fedora is going ahead without it for some, likely interesting, reason. In the end I guess it doesn't really matter as long as people eventually find out. The update-grub command apparently uses grub-mkconfig anyway.

When I used Debian, it had the generic update-grub command. So did Ubuntu, of course. To me at the time, Fedora appeared to be doing this grub2-whatever stuff by itself.

[tox]

i'll have to have a look at the ReadMe file on it to see if it still exists

[martyfelker]

There is no question anymore. Whether or no it conforms with the documentation the following command is what works in Fedora 126 Alpha 1

grub2-mkconfig -o /boot/grub2/grub.cfg

I have removed all files from the /boot/grub directory and the GRUB2 command installs the latest keren ...rc4.. if all the ...rce3.. are deleted from /boot.

Like many other I just tweak the grub.cfg file by removing the rhgb and quiet parameters from the generated file so I can what's happening. Actually this has another great side effect as the weird screen before the gdm login screen no longer appears.

Marty

[stoat]

Whether or no it conforms with the documentation the following command is what works in Fedora 126 Alpha 1

grub2-mkconfig -o /boot/grub2/grub.cfg

It conforms. I don't think anyone said otherwise. In fact, the erstwhile update-grub2 worked by running grub2-mkconfig. Besides, that command most often will be run automatically during kernel updates. Most of us will not need to run it manually any more often than we had to edit legacy GRUB's grub.conf or menu.lst (which for me isn't often). I guess my point is maybe that's why the Fedora thinkers dropped update-grub2.

I have removed all files from the /boot/grub directory and the GRUB2 command installs the latest keren ...rc4.. if all the ...rce3.. are deleted from /boot.

If you are referring to kernels in /boot, you should consider using yum to uninstall them instead. Deleting just files related to a kernel in /boot leaves behind millions of bytes related to its modules. But maybe I misunderstood what you meant.

Like many other I just tweak the grub.cfg file by removing the rhgb and quiet parameters from the generated file so I can what's happening.

Right, but it won't survive the next grub2-mkconfig command which will create a new grub.cfg and add those right back. There is a place to do that in /etc/default/grub and have grub2-mkconfig do it how you want it. To me, if we are going to manually edit grub.cfg, then there isn't much reason even to bother with GRUB 2.

[fpmurphy]

Right, but it won't survive the next grub2-mkconfig command which will create a new grub.cfg and add those right back. There is a place to do that in /etc/default/grub and have grub2-mkconfig do it how you want it. To me, if we are going to manually edit grub.cfg, then there isn't much reason even to bother with GRUB 2.

I have been using GRUB2 for some time and have found that the only way to avoid problems is to simply manually edit grub.cfg rather than have some script generate it for me.

[DBelton]

If you manually edit the grub.cfg, will grub automatically pick up the changes? Or does something else need to be done as well?

I do realize that if you manually update the grub.cfg, then the changes will get overwritten if grub2-mkconfig is run again.

[bscwuenn]

Yor are not supposed to manually change grub.cfg and yes the next time you run the update utility the file is overwritten.

[DBelton]

not supposed to change something in linux is just an open invitation for someone to change it

I'm certain that in my tweaking and changing things, I have modified some file that is not supposed to be manually changed before.

[zuchov]

not supposed to change something in linux is just an open invitation for someone to change it

I'm certain that in my tweaking and changing things, I have modified some file that is not supposed to be manually changed before.

Same here chap. I am not comfortable with GRUB 2, and have a hard time see the benefits of it. One machine of mine runs multiple OS's with Ubuntu 11 installed as lat of them. Kernelupdates on the other OS's always render myself changing the grub.cfg manually. I mean, even if it's script generated, every single menuentry is pretty straight forward, isn't it?

[DBelton]

I guess I am just used to changing /boot/grub/grub.conf and rebooting. The changes are seen without having to run anything else.

Actually, I see more benefits to using grub than with grub2..

[fpmurphy]

If you manually edit the grub.cfg, will grub automatically pick up the changes? Or does something else need to be done as well?

Yes. Nothing else needs to be done.

Either stick to manually editing grub.cfg or to the long-winded and official way. Do not try to mix both methods.

---------- Post added at 11:28 AM ---------- Previous post was at 11:16 AM ----------

One machine of mine runs multiple OS's with Ubuntu 11 installed as lat of them. Kernel updates on the other OS's always render myself changing the grub.cfg manually.

What you describe is the core fundamental design flaw with GRUB2. Each OS is expected to run its own grub-mkconfig to generate grub.cfg from grub configuration files that only exist within a particular OSes filesystem. Each OS, by default, has no knowledge of the other OSes GRUB configuration files.

I mean, even if it's script generated, every single menuentry is pretty straight forward, isn't it?

Yes, that is true.