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I installed Arch on my primary drive, /dev/sda. Installed Fedora to /dev/sdb last, as I wanted it to take the bootloader.

I think I did something wrong. I installed Fedora's bootloader to /dev/sdb, the MBR. I rebooted, and it went to Arch's grub screen. Should I have installed it to /dev/sda? If so, to the MBR, or /boot, or where?

Or, wait, I wonder what would happen if I changed my boot device order in BIOS... hhmmm...

Never mind, changed the boot order in BIOS and was able to get into Fedora.

Now just to edit Fedora's grub, and maybe reinstall it somewhere else. I'm thinking /boot in /dev/sda? Not sure? Any help on this appreciated. I'm going out for a while, but will be back in this evening.

Anyone?

Thanks!

With two or more Linux installations, I always use grub, put the master installation in the MBR of the first boot device, chainload the other grub(s) from that menu.

I'm not sure how you want to handle your dual-boot but I recommend this method. One advantage is you never have to edit the bootloader menu for a new kernel, as long as your distribution kernel install scripts make the edit automatically.

This is the chainloader syntax I use:


I've got six hard drives on three or four controllers and I've run into some confusion with how grub sees a partition. Also, I find grub invoked from the boot menu ("Press c for command line") will sometimes see a partition with a different number than the grub invoked after a kernel/OS is booted. To deal with that, one thing I will do is mark the / partition(s) by putting a file there. For example,

When booted in Fedora. Also, you can mount another installation / partition and mark it, for example:

The mount point is arbitrary but it must exist and it should be unused, atm. Then, call the grub shell at the boot menu by pressing c:

for example. Usually, quit grub with quit but I think you use Esc at the boot menu grub. The label file name is arbitrary but should be easy to remember and type.

You also need to know how grub sees your boot drive and you need to set the one you want. Each drive has an MBR and each partition has a boot sector. To install grub from the grub shell, you need to tell grub where the grub files are of the installation of interest, then where to install the grub code, to MBR or boot sector of a partition. Install the primary grub to MBR of the boot device, install the grub(s) you wish to chainload to the boot sector of the partition where that installations grub files are. For the secondary, chainloaded rc example on my machine:


Here, grub was installed to the boot sector of my rc installation / partition. It is an example how, booted to 2010, grub sees it as (hd3,0), per the find command output, while I have to put (hd1,0) in the chainloader stanza of my master grub menu.lst, as that is how grub sees it at boot time, before any kernel or modules are loaded. To install my 2010 grub to MBR of the boot device:

You have to be sure what grub is seeing and the find command is a good way to double-check.

So, to let Fedora take the boot loader, I installed in the wrong order, eh? Installed Arch first on my primary master, installed Fedora on the secondary master... each on the MBR of its own drive.

Crap.

It's not a big deal, you can re-install grub anywhere you want as long as you can get a grub shell: at the boot menu, booted to an OS, livecd, grub floppy, etc.

Then all I have to do is figure out that grub stuff you posted. I have no clue what it is, but I just don't "get" grub, at least when it comes to stuff like that. It's all greek to me. Maybe I haven't studied it enough, I dunno...