版本查看
[root@txt yum.repos.d]# cat /etc/redhat-release
CentOS Linux release 7.4.1708 (Core)
[root@txt yum.repos.d]# uname -a
Linux txt 3.10.0-693.el7.x86_64 #1 SMP Tue Aug 22 21:09:27 UTC 2017 x86_64 x86_64 x86_64 GNU/Linux
yum -y update
#升级所有包同时也升级软件和系统内核
#yum -y upgrade 只升级所有包，不升级软件和系统内核。
检查升级结果
[root@txt ~]# uname -a
Linux txt 3.10.0-1160.92.1.el7.x86_64 #1 SMP Tue Jun 20 11:48:01 UTC 2023 x86_64 x86_64 x86_64 GNU/Linux
[root@txt ~]# cat /etc/redhat-release
CentOS Linux release 7.9.2009 (Core)
