什么能真正触发系统目标单元(如suspend.target )的活动状态？

Question

我有一台服务器，显然是随机进入睡眠状态，我无法在系统日志中找出究竟是什么触发了这个状态。

因此我的问题是:什么进程(Es)或事件(S)能够在Ubuntu22.04上实际触发以下systemd目标进入active状态(例如使系统进入睡眠状态)的状态？

$ systemctl status suspend.target 
○ suspend.target - Suspend
     Loaded: loaded (/lib/systemd/system/suspend.target; static)
     Active: inactive (dead)
       Docs: man:systemd.special(7)

Answer 1

那会是

systemctl enable suspend.target 

请注意，如果系统服务有故障，enable将出错，并将显示如下：

$ systemctl enable suspend.target 
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.

如果是的话.这个问题需要第一次解决。

Answer 2

从我所看到的是节约能源触发了它。在阅读man systemd.special时，您可以看到suspend.target拉入sleep.target，并在需要时被调用。

   suspend.target
       A special target unit for suspending the system. This pulls in
       sleep.target.
   sleep.target
       A special target unit that is pulled in by suspend.target,
       hibernate.target and hybrid-sleep.target and may be used to hook
       units into the sleep state logic.

它是由系统服务管理器管理的Special System Units的一部分。

运行systemctl start systemd-suspend.service将使您的系统正常休眠，因为它现在是活动的，因此它必须保持不活动状态，直到需要为止。