New install of 17.1 Cinnamon. Other distro is Slack 14. GRUB2 installed by choice into the root device of Mint. MBR contains Old Grub. There are 2 ways I can boot into Mint:

1. Point the old grub on MBR to /boot/vmlinuz-3.13.0-37-generic and initrd.img-3.13.0-37-generic in the Mint root partition. Works fine.

2. Point the old grub to /boot/grub/i386-pc/core.img in the Mint root partition. Also works, though it takes a few secs longer.

Question: Is there any functional difference between these two boot methods? I don't see any obviously different behavior, but I still wonder.

Your installation of Mint 17.1 seems not successful.

I think you mis-read his post. He said both options do boot.

No. Have the same thing with Grub Legacy booting Ubuntu. The first option directly boots, the second option is more like a chainload entry and when I select it, I get the Ubuntu boot menu with various options.

1 members found this post helpful.

I have read the first post.

But it makes no sense to me installing two bootloaders in two places.

If it is a actual computer, UEFI is the best way.

It might not be a uefi computer.
Makes perfect since IMO. I have a similar setup and allows for a distro to update it's own grub menu during updates without having to go and update grub in the distro with the bootloader in the mbr, which I tend to forget to do from time to time.

If you have multiple operating systems as is the case here, installing a bootloader to the root partition of the second system allows you to chainload it. The OP has two entries to boot Mint in his Grub Legacy. There is no need to do it, probably just to test. The first method will boot a few seconds faster as it doesn't go to the menu of the second OS as the second option does.

Hardwareinfo?

Just to be clear, this isn't a UEFI box. The two boot loaders are an "accident of history." Original distro (Slack 14) installed legacy grub in MBR. Some time later I installed Mint 17.1 in unused space on the same physical drive. During the Mint install I selected the Mint root partition for grub2, because I didn't want to screw up my working MBR. Simple as that.

I'm marking this thread as SOLVED, because I believe my original question has been answered.