无外网环境centos升级内核内核选择https://elrepo.org/linux/kernel/el7/x86_64/RPMS/kernel-lt（lt=long-term）长期有效kernel-ml（ml=mainline）主流版本用虚拟机将内核包下载到本地wgethttps://elrepo.org/linux/kernel/el7/x86_64/RPMS/kernel-ml-5.11.