查看可用内核 awk -F\' '$1=="menuentry " {print i++ " : " $2}' /etc/grub2.cfg 列表: 0 : CentOS Linux (5.7.4-1.el7.elrepo.x86_64) 7 (Core) 1 : CentOS Linux (3.10.0-1062.9.1.el7.x86_64) 7 (Core) 2 : CentOS Linux (0-rescue-0ea734564f9a4e2881b866b82d679dfc) 7 (Core) 修改开机默认…