I have Mint Linux installed on an external hard. My Dell laptop has Win7 OS. I have a dual boot setup via easyBCD with Mint as the default OS. Recently, my external hard drive has failed to boot into Mint and instead I boot into the grub> command line. How do I repair the grub boot loader? I'm not aware of anything that I did that
precipitated the change. I've had this dual boot setup in operation for a substantial period of time before this problem developed and Mint failed to boot. I have tried a few suggestions in various posts to no avail.

Thanks

EasyBCD is windows software which basically chainloads to another OS. Where did you install Grub2 when you installed Mint? It might be as simple as setting the external to first boot priority in the BIOS. Do you get just the grub prompt immediately upon selecting Mint in EasyBCD? Either your entry in EasyBCD got messed up or some problem with the Grub configuration file and with the information you posted, we would just be guessing. Best thing is to post more details such as the output from the boot repair script which you can get from the link below. Us your Mint DVD to boot and download and run it and make sure you select to Create BootInfo Summary rather than try any repairs. Post a link to the output here.

https://help.ubuntu.com/community/Boot-Repair

Thank for your reply, link is:

http://paste2.org/HsgOAe7b

Your boot repair shows Mint on sdb1, the first partition of the second (1TB) drive. It is pointing to the core.img file on sdb5 which shows as an Ubuntu installation?? Do you have a bootable installation of Ubuntu? If you do, just boot that and run sudo update-grub from it and see if you get an entry for Mint on reboot with the 1TB drive set to first boot priority. Did you make any changes to EasyBCD? Any reason you neglected to mention the Ubuntu install? When was that and how did you try to boot it?

Mint often shows its roots/heritage - even the UEFI boot entry from memory.
I haven't used EasyBCD in a while, but it used to require the loader to be chainloaded (grub in this case) be in the partition record rather than MBR - which grub[2] objects to and has to be forced. May have changed - like I said, was a while ago.

I do not have a bootable installation of Ubuntu. Yes, I did try a few things with easyBCD before seeking help.

mint@mint ~ $ sudo update-grub
/usr/sbin/grub-probe: error: failed to get canonical path of `/cow'.

So where is Mint, sdb1 or sdb5. I'm wondering how the Grub code in the MBR of the external got to point to sdb5? Did you try to install something to sdb5 or is that actually where the Mint install is? How are you running sudo update-grub? The message you posted would indicate you are running it from a Live CD. That won't work. The link below gives a number of methods to try including using the boot repair.

https://help.ubuntu.com/community/Gr..._Broken_System

Your Grub code in the mbr of the external drive is looking for a grub.cfg file on sdb5 which according to the boot repair output does not exist. Whatever you did with EasyBCD needs to be undone.

Back story: Most forums ask that you do a search before posting. After searching a number of posts, I made several efforts to correct the problem based on the posts. Obviously, these efforts were unsuccessful and I cannot specifically say whether they exacerbated the original problem or not. I still do not know what precipitated the problem.

To make a long story short, I downloaded and ran the Boot Repair disk which fixed the problem. I changed the bios to boot from the usb drive and will now use the linux boot loader in lieu of easyBCD.

Thank you yancek and syg00 for your support!

Note: Do I need to close the post?

Glad you got it working. The standard boot repair will install Grub code to the MBR of all drives so remember that. If you decide to remove Mint and keep windows, you need to repair the MBR on windows first or you will have an unbootable machine. If you don't have the windows installation media, you should be able to download some type repair disk. I think Hirens has the necessary software. Make sure you always have something available to make this type repair. The boot repair is pretty handy so you should keep it on a CD or flash drive.

Moved: This thread is more suitable in <Linux Mint> and has been moved accordingly to help your thread/question get the exposure it deserves.