Windows/linux (ubuntu/linuxMint) dual systems cannot start the ultimate solution

Windows/linux (ubuntu/linuxMint) dual system cannot start the ultimate solution hardware configuration is as follows: CPU: AMD A10-5800K (APU, HD 7660D) motherboard: GIGABYTE (GIGABYTE) F2A85X-D3H motherboard (dashboard) memory: Zhiqi (G. SKILL) DDR3 1600 8G (4G x 2 dual-channel) software configuration: first install windows 7 with UEFI + GPT, then install ubuntu, and use boot-repair to repair the boot. Later, I tried to change the Linux mint and thought the partition for ubuntu was unreasonable. By the way, I changed the partition, that is, the location of the original/boot partition had changed. Then you can install linuxMint normally. Unfortunately, it will be a tragedy after the restart. No cute grub boot interface is displayed after the restart. Instead, the following error message is displayed: [plain] error: unknown filesystem grub rescue> the following three methods are provided to solve startup problems similar to this one (You may not have the same problem as me, but as long as it is a grub boot problem, can be solved in the following ways): 1: Quiet: boot-repair boot with the installation media boot (I use a USB flash disk to install the system, if you use a CD is OK) go to the linux environment, just try it out, and choose not to install it. Ubuntu/linuxMint will provide you with a pre-installation desktop environment, and call up the terminal after entering (you can press ctrl + alt + T). Of course, you must first connect the network, run the following command to start boot-repair: [plain] $ sudo add-apt-repository ppa: yannubuntu/boot-repair & sudo apt-get update $ sudo apt-get install-y boot-repair & (boot-repair &) You should get a similar interface, what are you waiting for? Click "Recommended repair". After a few minutes, you will get a prompt similar to the following: Click OK and restart to check whether the boot is successful, if you still cannot boot, use the following steps 2: Getting Better: Use chroot to install the desktop environment in linux, connect to the Internet, and call out the terminal. First, confirm the partition in which your system is installed. The simplest way is to use GParted Based on the partition size. For example, the above is my partition. If you cannot use gparted, you can use fdisk or blkid to see: [plain] $ sudo fdisk-l/dev/sda $ sudo blkid. For example, my partition plan here is: mount sda5 to/sda8 to/usr sda9 to/tmp to prepare for chroot: [plain] $ sudo mkdir-p/mnt/mint $ sudo mount/dev/sda5/mnt/mint/# sda5 corresponds to the/directory of the real system $ sudo mount/dev/sda9 /mnt/mint/tmp # sda9 corresponds to the/tmp directory of the real system $ sudo mount/dev/sda8/mnt/mint/usr $ sudo mount-t pr Oc none/mnt/mint/proc $ sudo mount-o bind/dev/mnt/mint/dev $ sudo mount-o bind/sys/mnt/mint/sys $ sudo mount- t devpts/mnt/mint/dev/pts because I didn't partition/boot separately, so/boot is in sda5. The above is mainly to mount the necessary File System for the chroot system. If you have other partitions that are separately partitioned, in particular, partitions such as/etc/boot/usr must be mounted to the corresponding directory. Then change root: [plain] $ sudo chroot/mnt/mint enter the preceding command and a different prompt appears, which means you have successfully changed. Here/mnt/mint is the mount point corresponding to the real system/partition. Then, run the following command to repair grub: [plain] # grub-install -- recheck/dev/sda # update-grub and then exit the change root environment, enter the following command in sequence: [plain] # sync # exit this time, it should be returned to the original terminal, and then unmount the previously mounted partition in reverse order: [plain] $ sudo umount/mnt/mint/dev/pts $ sudo umount/mnt/mint/dev $ sudo umount/mnt/mint/sys $ sudo umount/mnt/mint/ proc $ sudo umount/mnt/mint/usr $ sudo umount/mnt/mint/tmp $ sudo umount/mnt/mint restart to check the effect, basically, startup problems are fixed in this way, If you still cannot start it, you can only use the third method. 3: Heaven and Earth are the same: You can delete grub and reinstall grub manually and automatically. The simplest automatic method is provided here. The preceding steps are the same as step 1. First, enter the linux installation desktop environment, connect to the Internet, and call up the terminal. Start boot-repair: [plain] $ sudo add-apt-repository ppa: yannubuntu/boot-repair & sudo apt-get update $ sudo apt-get install-y boot-repair & (boot-repair &) instead of clicking "Recommended repair", click "Advanced options" next to the triangle symbol. The following interface is displayed. Switch to the "Grub Options" tab, select the first item "Purge Grub... ", the latest may be different from the following figure, but there is still the Purge: Click apply, it will automatically help you work, during which a dialog box will pop up, you need to put the command in the pop-up dialog box in the terminal for execution. Just copy and paste the command as needed (copy and paste it): Of course, the last dialog such as method 1 will also pop up when it is finished, you don't need to worry about it. Restart it directly and you will be pleasantly surprised. Note: My startup problem is solved in the last way. The previous two methods do not work for the system after the partition is adjusted, especially when the UEFI + GPT partition is used, it may be caused by a change in the/boot position.