explain:

1. Use the console terminal to manage the connection server.

2. CentOS 7 uses grub2 as the boot program, so it is different from CentOS 6. It does not modify/etc/grub.conf to modify the startup item.

Specific operation steps:

Check how many cores are in the system: cat/boot/grub2/grub.cfg | grep menueentry

The configuration starts from the default kernel. The kernel name of the following command is replaced according to the actual name found inside the system:

Verify whether the configuration is successful: grub2-editenv list