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I have a MacBook Pro, and I use rEFIned to dual-boot Ubuntu and Mac OS X. In case I ever messed anything up, I installed Ubuntu on an external hard drive. However, I messed up the setup so I installed GRUB onto the hard drive. Now when I boot GRUB without my external hard drive connected, GRUB goes into grub rescue with "Cannot find device." I can still boot any of my OSes if the hard drive is plugged in.

How can I fix this? Will uninstalling GRUB from the hard drive help, or do I have to configure rEFIned differently?

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If I understand your setup, GRUB is useless unless the external hard disk is plugged in, so the easiest and safest solution is simply to ignore the Linux/GRUB entry in rEFInd when the external disk is disconnected. If there's some reason why this is undesirable or impossible, please elaborate.

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The problem is that I can't boot the Ubuntu install on my internal drive without my external hard drive plugged in. How would I go about changing the boot device for GRUB? – Tobi Hahn May 14 '13 at 23:22
That depends on whether it's a BIOS-mode or EFI-mode GRUB install. It might be easier to configure rEFInd to launch your Linux kernels directly. You'll need to install an EFI driver for your Linux root (/) (or /boot if it's a separate partition) filesystem and run the script that comes with rEFInd to create a /boot/refind_linux.conf configuration file. Thereafter, you should be able to launch Linux directly using rEFInd, without using GRUB. – Rod Smith May 14 '13 at 23:31
This sounds like it will be easier and better than using GRUB anyway. I don't really like going through two separate bootloaders, so this is an ideal solution. Thanks! – Tobi Hahn May 14 '13 at 23:34

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