3.1. erase /dev/sda in case there are old partitions on it: dd if=/dev/zero of=/dev/sda bs=1M count=1 3.2. Create 3 primary partitions on /dev/sda as dev/sda1,sda2,sda3 (the size is 100M, 30M and 70M), and toggle sda1 to be bootable

And the most strange thing is that ls command shows nothing in grub-rescue cli ---- as someone says, it should show disk list.

3.1. erase /dev/sda in case there are old partitions on it: dd if=/dev/zero of=/dev/sda bs=1M count=1

3.2. Create 3 primary partitions on /dev/sda as dev/sda1,sda2,sda3 (the size is 100M, 30M and 70M), and toggle sda1 to be bootable

And the most strange thing is that ls command shows nothing in grub-rescue cli ---- as someone says, it should show disk list.

I have googled a lot for this problem. I found this, but it didn't solve my problem. Other solutions suggest me to reinstall grub (run grub-install), which didn't help neither.

I have googled a lot for this problem. I found this, but it didn't solve my problem. Other solutions suggest me to reinstall grub (run grub-install), which didn't work either.