RHEL 7.9 上沒有網路管理器服務

有一個 RHEL 7.9 伺服器。似乎已安裝 networkmanger 軟體包但未添加任何服務。有沒有辦法可以手動添加服務？

#  yum install NetworkManager
Loaded plugins: langpacks, product-id, search-disabled-repos, subscription-manager

This system is not registered with an entitlement server. You can use subscription-manager to register.

local                                                                                                                                                                                     | 2.8 kB  00:00:00
Package 1:NetworkManager-1.18.8-1.el7.x86_64 already installed and latest version
Nothing to do

# systemctl start networkmanager
Failed to start networkmanager.service: Unit not found.

# cat /etc/*release
NAME="Red Hat Enterprise Linux Server"
VERSION="7.9 (Maipo)"
...

嘗試：

systemctl daemon-reload
systemctl status NetworkManager
# start if it is there
systemctl start NetworkManager

如果它不起作用檢查單元文件：

systemctl list-unit-files | grep -i network

如果它不存在檢查

/usr/lib/systemd/system/
/etc/systemd/system

任何 .service 文件的目錄。

如果您需要創建 .service 文件，這裡是一個模板：

[Unit]
Description=<description about this service>

[Service]
User=<user e.g. root>
WorkingDirectory=<directory_of_script e.g. /root>
ExecStart=<script which needs to be executed>
Restart=always

[Install]
WantedBy=multi-user.target

引用自：https://unix.stackexchange.com/questions/699966