Por que o systemctl não fornece uma mensagem de erro quando todas as tentativas a seguir de ativar ou reativar o [email protected] falham
~ $ systemctl list-unit-files | grep enabled
[email protected] enabled
[email protected] enabled
systemd-fsck-root.service enabled-runtime
remote-fs.target enabled
~ $ sudo systemctl enable [email protected]
~ $ systemctl list-unit-files | grep enabled
[email protected] enabled
[email protected] enabled
systemd-fsck-root.service enabled-runtime
remote-fs.target enabled
~ $ sudo systemctl unmask [email protected]
~ $ sudo systemctl reenable [email protected]
Removed /etc/systemd/system/multi-user.target.wants/[email protected].
Created symlink /etc/systemd/system/multi-user.target.wants/[email protected] → /usr/lib/systemd/system/[email protected].
~ $ systemctl list-unit-files | grep enabled
[email protected] enabled
[email protected] enabled
systemd-fsck-root.service enabled-runtime
remote-fs.target enabled
~ $ sudo systemctl start [email protected]
~ $ systemctl list-unit-files | grep enabled
[email protected] enabled
[email protected] enabled
systemd-fsck-root.service enabled-runtime
remote-fs.target enabled
O link simbólico criado acima se refere a /usr/lib/systemd/system/[email protected], que possui essas características.
~ $ systemctl -a list-unit-files|grep [email protected]
[email protected] static
~ $ systemctl status [email protected]
Failed to get properties: Unit name [email protected] is neither a valid invocati>
~ $ sudo systemctl enable [email protected]
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:
1) A unit may be statically enabled by being symlinked from another unit's
.wants/ or .requires/ directory.
2) A unit's purpose may be to act as a helper for some other unit which has
a requirement dependency on it.
3) A unit may be started when needed via activation (socket, path, timer,
D-Bus, udev, scripted systemctl call, ...).
4) In case of template units, the unit is meant to be enabled with some
instance name specified.