Hi,

my server currently runs Centos6. I have been playing about with Centos7 in VirtualBox for a few weeks now and would like to install. In the short term I would like to dual boot with 6 just in case.

I have documented my installation procedure so that should be easy enough. However, I do not see any options to locate a bootloader - this may be due to the VM. Does the installer just install a bootloader and recognise existing distros? Or have I missed something at install time? I have the "everything" ISO.

Cheers

Usually the bootloader install just picks up existing entries or OS's and incorporates them.

I don't want to jinx you, but so far this has worked pretty flawlessly for me. I just installed RHEL7 alongside Fedora last week or the week before and it auto-detected everything without issue.

Now as for there being extra repositories ready for me to use in RHEL7 ... well, that's another story... :-)

What I am describing is how most distributions work and I think CentOS follows this pattern. My description is also for x86 architecture only.

The installer will run the grub bootloader. The grub bootloader will find all of your installed operating systems and describe them in grub configuration files located in /boot/grub. Then grub will place a boot record on your MBR which points to the grub configuration file called /boot/grub/grub.config.

If you install two different versions of CentOS then each install will configure and install grub. (The installer might give you the option of skipping installing grub.) Which ever install you do last will be the one with a bootloader on the MBR. I suggest that you do CentOS 7 last so that you will be using the latest version of grub.

But you don't have to do the installs in that order. When you finish all of the installs you can boot into whichever distribution you want to supply grub and go through the grub install process. Here is a description of the grub install process.

http://wiki.centos.org/HowTos/GrubInstallation

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Steve Stites

Thanks. Centos6 will still be there so if I don't automatically get a dual boot I can tinker with grub - it is not the end of the world. The rest of the house relies on this server so I don't want it unavailable.

Before I install I need to resize one of the disks and that is causing me grief now so I need to concentrate on that first.

Cheers

Update. I wrote a procedure with Centos7 under VirtualBox. There IS an option to specify the boot disk. When you click on "Installation Destination" there is a link right at the bottom of the screen "Full Disk Summary and Bootloader".

Sorted!