[PLUG] Redhat 7.3.92 so far...

[Eric Harrison]

On 15 Jul 2002, Alan wrote:

>> Try fiddling around with GRUB for a while. I won't use LILO anymore,
>> GRUB is much harder to screw up - and if you do screw it up you can 
>> drop down to a command prompt giving you a chance to fix the problem
>> and get the machine back up and running.
>
>I need to find a good overview of how GRUB is supposed to work.  The
>commands are a bit alien to me.

Here's 99% of what you need to know about grub under "usual" conditions:

 * The config file is /boot/grub/grub.conf (symlinked to /etc/grub.conf),
   you should be able to get the syntax down in about 15 seconds. The
   "default=?" line is the default kernel, as listed counting from zero.
   (i.e. the first kernel listed is "0", the second is "1", and so on)

 * you don't need to run a command after editing the grub.conf file, GRUB
   reads it when the system boots

 * to modify the boot parameters (say like the old "LILO: linux single"),
   use the arrow keys to select the kernel you want, hit "e" to edit the
   config, select the portion you want to edit (usually the second line which
   contains the kernel paramaters), hit "e" to edit it, hit return when you're
   done, then hit "b" to continue booting. It's fairly obvious once you've
   done it once or twice.

 * I don't want to reboot right now, am too lazy to RTFM, and can't remember
   off the top of my head how to drop down to the "boot monitor" prompt.
   I believe it's listed right on the initial bootup screen. There is a 
   help facility that explains the basics of each command. The big "gotcha"
   for me was that if /boot is a seperate partition, grub acts as if it
   chrooted to there (i.e. "/boot/vmlinuz" is "/vmlinuz" to grub).


-Eric