在系统中使用虚拟机，之前使用的时virt-manager，但红帽子的文档中说使用cockpit进行逐渐替代，因此个人也逐渐转移自己的使用方法。但是cockpit这个服务配置自启动时遇到了问题，使用'sudo systemctl enable cockpit'报错如下：
The unit files have no installation config (WantedBy=, RequiredBy=, Also=,
Alias= settings in the [Install] section, and DefaultInstance= for template
units). This means they are not meant to be enabled using systemctl.
Possible reasons for having this kind of units are:
• A unit may be statically enabled by being symlinked from another unit's
.wants/ or .requires/ directory.
• A unit's purpose may be to act as a helper for some other unit which has
a requirement dependency on it.
• A unit may be started when needed via activation (socket, path, timer,
D-Bus, udev, scripted systemctl call, ...).
• In case of template units, the unit is meant to be enabled with some
instance name specified.根据提示服务的unit文件中'[Install]'单元部分找不到'WantedBy=, RequiredBy=, Also=, Alias='的相关设置，所以不能使用systemctl来配置自启动，修改文件'/usr/lib/systemd/system/cockpit.service'，末尾添加内容如下：
[Install]
WantedBy=multi-user.target
