Wants=
A weaker version of Requires=
. Units listed in this option will be started if the configuring unit is. However, if the listed units fail to start or cannot be added to the transaction, this has no impact on the validity of the transaction as a whole. This is the recommended way to hook start-up of one unit to the start-up of another unit.
Note that dependencies of this type may also be configured outside of the unit configuration file by adding symlinks to a .wants/
directory accompanying the unit file. For details, see above.
启动一个服务时可以连带启动其他服务,但是其他启动不成功并不影响这个服务的启动