Background: win10 has been installed on the c drive, and the iso file of the ubuntu system installation is placed on the d drive. I want to install the ubuntu system of the D disk to the external mobile hard disk without using the U disk.
1. Win10 partitions the mobile hard disk: https://www.laomaotao.net/new/2019/1114/7732.html . Separate a space 100G for the ubuntu system to be installed
2. Unzip all the files in the iso to the root directory of the d drive (it is to put all the contents in the decompressed folder, excluding the outermost folder itself.). The iso file is also placed in the root directory of the d drive
3. Easy bcd increases the boot entry. Reference https://zhuanlan.zhihu.com/p/37277742
4. Then select the startup item just added when starting up
5. Partition reference: 4 partitions in total: (I am in the first step)
/ xfs 50G (Don't believe 20G on the Internet, not enough !!)
/boot ext4 200M
swap 32G (twice the memory)
/ home The remaining space. Close to 50G
报错：The partition /dev/sdb1 assigned to / starts at an offset of 3584 bytes from the minimum alignment for this disk, which may lead to very poor performance
Note: If you encounter the above 4kb alignment problem : adjust the format of the main partition / to xfs. Instead of ext4. (Other ways to solve this problem online: tried diskgenius formatted into linux native method failed: because after doing so, it must be reformatted when installing under ubuntu. The check box cannot be changed)
6. After the installation is complete, the bootmgr is missing problem at startup: refer to my previous blog to use boot-repair to repair it.
