升级centos遇到问题

yum.noarch 0:3.4.3-168.el7.centos
yum-plugin-fastestmirror.noarch 0:1.1.31-54.el7_8
zlib.x86_64 0:1.2.7-21.el7_9
zlib-devel.x86_64 0:1.2.7-21.el7_9

跳过（依赖问题）:
postfix.x86_64 2:2.10.1-9.el7

替代:
NetworkManager.x86_64 1:1.0.6-27.el7 grub2.x86_64 1:2.02-0.29.el7.centos
grub2-tools.x86_64 1:2.02-0.29.el7.centos iwl7265-firmware.noarch 0:22.0.7.0-43.el7
pygobject3-base.x86_64 0:3.14.0-3.el7 rdma.noarch 0:7.2_4.1_rc6-1.el7

完毕！
[root@zlg yum.repos.d]#