Hi,
I'm posting to the Red Hat forum because there is no separate Centos forum.
I recently installed Fedora 20 on my local Windows 7 machine and I'm using GRUB2 to boot both systems. Fedora was installed on unused space on the single hard drive.
Everything works well. The installer was a pleasure to work with.
Since I'm also running a Centos 6 VPS remotely, I'd like to install Centos 6 on the same local machine as Fedora and Windows 7. I still have plenty of unallocated space on my hard drive
Since Centos 6 uses GRUB 1, I'm wondering how I might handle the installation. GRUB 2 is currently on the MBR. Could I somehow use GRUB2 to boot all three OS's. Or, will the Centos installer overwrite the MBR with GRUB1 ? If so, would GRUB 1 handle booting Fedora 20, Centos 6 and Windows 7 ? Would I have to modify some of the GRUB configuration files?
Any insight would be much appreciated.
Hank

You might want to think about installing it as a virtualised guest. Then you don't have to worry about it at all.
Been a while since I installed CentOS, but
- yes the default install will overwrite the MBR.
- grub legacy can boot all 3, but F20 using os-prober and grub2 is better, and automatic.
- yes, you'd have to update menu.lst (probably still called grub.conf in CentOS).

You have the option to not install a boot-loader at all in the CentOS installer, but if you have the option it might be a better bet to install to the root partition if you have that option. Check the drop-down list to see what options you get.

I forget where exactly the choice is in the Centos install sequence, but there is a choice to install the first sector of legacy Grub in the boot sector of the partition where the rest of legacy Grub is installed, rather than the default location in the MBR.

In Grub2 it is easy to configure a menu item to boot Centos 6 directly skipping legacy Grub. But you may prefer to put in a menu item to chainload to the boot sector of the partition containing Grub. That would give you the Grub2 menu followed by the legacy Grub menu (you can make the legacy Grub menu fast and silent if you like).

I just installed CentOS for the first time last week and it does have an option to install Grub to the root partition. The default is to the mbr so you need to pay attention during the install to make the selection. If you want the Fedora Grub2 booting, you will need to boot into Fedora after installing CentOS and run the grub-mkconfig command so that Fedora can add CentOS to its boot menu. See link below:

http://fedoraproject.org/wiki/GRUB_2

Note that on Fedora that would be grub2-mkconfig (yes, I know it's lame, but it's what we have to live with). The wiki should have the correct (for Fedora) command(s).

Thanks for the quick replies. You have given me a lot to think about. After I decide on the approach I'm going to take I shall post my results.
Hank