Ubuntu boot FIX: for grub rescue| | Grub Not found| | Unknown filesystem type of error

Introduction

Ubuntu is generally guided through grub. Grub is divided into three types: GRUB,GRUB2, and Grub for DOS (grub4dos).
Recently under Windows to distinguish a larger point 100G out, ready to install WIN10, when I started Ubuntu, there was a problem: Grub not found ===>grub rescue.
This problem occurs because grub cannot find the partition where Ubuntu is located (this usually happens because you have resized the partition and the grub configuration has not been adjusted accordingly). In general, there are 2 ways to solve this problem:
1. Use EASYBCD software to adjust;
2. Re-specify the partition by command at the command line;

Use EASYBCD software to adjust

1. Baidu Search EasyBCD 2.2, download and install (freeware). Run as Administrator;
2. Click "Add new Entry" as shown in:
   
3. In the operating system options, select "Linux/bsd":
   
4. Type a column with "GRUB2" selected, the name is filled in, the drive selects "Auto-locate and load", and finally "Add Entry" is selected.
5. So, the problem is solved, restart the computer, choose Ubuntu
6. Finally, this method sometimes fails.

To reassign a partition by command at the command line

1. Because in rescue mode, only a small number of basic commands are available, a certain operation must be done to load the module, and then enter the normal mode;
2. The commands that can be used in rescue mode are: Set,ls,insmod,root,prefix (setting the boot path);

The command explanation in Grub Rescue mode:
LS: View system device status
Set: View boot path and partition
Root: Set GRUB boot partition
Prefix: Setting the boot path for grub
Insmod: Load Module

1. The first is to find the partition where grub is located. Use the LS command: Grub rescue>ls, and then list all the partitions on your disk, such as mine: (HD0,MSDOS10), (HD0,MSDOS9) ...;
2. Then, enter the following command: LS (HD0,MSDOS10)/grub or LS (HD0,MSDOS10)/boot/grub (usually the latter). It must be noted here: This command is just a template, everyone's computer may be different, Please enter the command according to your computer. If the system returns: Unknown filesystem, continue to enter the next partition listed until a partition is displayed that is not unknown filesystem, but other content, the partition where grub is located is found and continues;
3. Grub rescue> Set root= (HD0,MSDOS10);
4. Grub rescue> Set prefix= (HD0,MSDOS10)/boot/grub or may be grub rescue> set prefix= (HD0,MSDOS10)/grub this to see where the specific grub is located;
5. Grub rescue> Insmod Normal;
6. Grub rescue> Normal;
7. At this point, you should have entered the normal mode of Ubuntu system, enter the system!

Copyright NOTICE: This article for Bo Master original article, without Bo Master permission not reproduced.

Ubuntu boot FIX: for grub rescue| | Grub Not found| | Unknown filesystem type of error